ICND 2 Book Questions

1. Barney is a host with IP address 10.1.1.1 in subnet 10.1.1.0/24. Which of the following are things that a standard IP ACL could be configured to do? (Choose two answers.) a. Match the exact source IP address. b. Match IP addresses 10.1.1.1 through 10.1.1.4 with one access-list command without matching other IP addresses. c. Match all IP addresses in Barney's subnet with one access-list command without matching other IP addresses. d. Match only the packet's destination IP address.

1. A and C. Standard ACLs check the source IP address. The address range 10.1.1.1- 10.1.1.4 can be matched by an ACL, but it requires multiple access-list commands. Matching all hosts in Barney's subnet can be accomplished with the access-list 1 permit 10.1.1.0 0.0.0.255 command.

1. Which of the following attributes do QoS tools manage? (Choose three answers.) a. Bandwidth b. Delay c. Load d. MTU e. Loss

1. A, B, E. QoS tools manage bandwidth, delay, jitter, and loss.

1. Which of the following IEEE 802.1D port states are stable states used when STP has completed convergence? (Choose two answers.) a. Blocking b. Forwarding c. Listening d. Learning e. Discarding

1. A, B. Listening and learning are transitory port states, used only when moving from the blocking to the forwarding state. Discarding is not an 802.1D STP port state.

1. Which of the following network commands, following the command router eigrp 1, tells this router to start using EIGRP on interfaces whose IP addresses are 10.1.1.1, 10.1.100.1, and 10.1.120.1? (Choose two answers.) a. network 10.0.0.0 b. network 10.1.1x.0 c. network 10.0.0.0 0.255.255.255 d. network 10.0.0.0 255.255.255.0

1. A, C. The EIGRP network command supports a parameter of a classful network, enabling EIGRP on all interfaces in that classful network or an address and wildcard mask. In the latter case, interface IP addresses that match the configured address, when applying ACL-like logic with the wildcard mask, match the command.

1. Router 1 has a Fast Ethernet interface 0/0 with IP address 10.1.1.1. The interface is connected to a switch. This connection is then migrated to use 802.1Q trunking. Which of the following commands could be part of a valid configuration for Router 1's Fa0/0 interface? (Choose two answers.) a. interface fastethernet 0/0.4 b. dot1q enable c. dot1q enable 4 d. trunking enable e. trunking enable 4 f. encapsulation dot1q 4

1. A, F. Of all the commands listed, only the two correct answers are syntactically correct router configuration commands. The command to enable 802.1Q trunking is encapsulation dot1q vlan_id.

1. A Layer 2 switch examines a frame's destination MAC address and chooses to forward that frame out port G0/1 only. That action is an action that occurs as part of which plane of the switch? a. Data plane b. Management plane c. Control plane d. Table plane

1. A. The data plane includes all networking device actions related to the receipt, processing, and forwarding of each message, as in the case described in the question. The term table plane is not used in networking. The management plane and control plane are not concerned with the per-message forwarding actions.

1. A colleague mentions using a client VPN. Which of the following protocols or technologies would you expect your colleague to have used? a. SSL b. IPsec c. GRE d. DMVPN

1. A. The term client VPN typically refers to a VPN for which one endpoint is a user device, such as a phone, tablet, or PC. In those cases, SSL is the more likely protocol to use. SSL is included in browsers, and is commonly used to connect securely to websites. GRE along with IPsec is more likely to be used to create a site-to-site VPN connection. Similarly, Dynamic Multipoint VPN (DMVPN) could also use IPsec, but in a multipoint topology, and not specifically for client devices.

1. Which of the following topology terms most closely describe the topology created by a Metro Ethernet Tree (E-Tree) service? (Choose two answers.) a. Full mesh b. Partial mesh c. Hub and Spoke d. Point-to-point

1. B, C. A Metro Ethernet E-Tree service uses a rooted point-to-multipoint Ethernet Virtual Connection (EVC), which means that one site connected to the service (the root) can communicate directly with each of the remote (leaf) sites. However, the leaf sites cannot send frames directly to each other; they can only send frames to the root site. Topology design like this that allow some but not all pairs of devices in the group to communicate is called a partial mesh, or hub and spoke, or in some cases a multipoint or point-to-multipoint topology. Of the incorrect answers, the full mesh term refers to topology designs in which each pair in the group can send data directly to each other, which is typical of a MetroE E-LAN service. The term point-to-point refers to topologies with only two nodes in the design, and they can send directly to each other, typical of a MetroE E-Line service.

1. Which of the following VTP modes allow VLANs to be configured on a switch? (Choose two answers.) a. Client b. Server c. Transparent d. Dynamic

1. B, C. VTP has three modes: server, client, and transparent. Only server and transparent mode switches can be used to configure VLANs; that is, to create the VLAN, delete the VLAN, and assign a VLAN a name. Client mode switches cannot configure VLANs. Also, there is no such mode as dynamic mode.

1. On a 2960 switch, which of the following commands change the value of the bridge ID? (Choose two answers.) a. spanning-tree bridge-id value b. spanning-tree vlan vlan-number root {primary | secondary} c. spanning-tree vlan vlan-number priority value d. set spanning-tree priority value

1. B, C. You cannot set the system ID part of the bridge ID (BID). However, you can set the priority part of the BID, the first 16 bits, in two ways. One way sets it directly (spanning-tree vlan priority), whereas the other tells the switch to figure out a priority setting that either makes the switch root (spanning-tree root primary) or the backup (spanning-tree root secondary).

1. Which of the following Internet edge designs include connections to two ISPs? (Choose two answers.) a. Single homed b. Single multihomed c. Dual homed d. Dual multihomed

1. B, D. The word multihomed refers to designs in which the enterprise connects to (at least) two ISPs. The two choices that include the term homed refer to designs that connect to a single ISP.

1. In a LAN, which of the following terms best equates to the term VLAN? a. Collision domain b. Broadcast domain c. Subnet d. Single switch e. Trunk

1. B. A VLAN is a set of devices in the same Layer 2 broadcast domain. A subnet often includes the exact same set of devices, but it is a Layer 3 concept. A collision domain refers to a set of Ethernet devices, but with different rules than VLAN rules for determining which devices are in the same collision domain.

1. Which of the following cloud services is most likely to be used for software development? a. IaaS b. PaaS c. SaaS d. SLBaaS

1. B. PaaS (Platform as a Service) supplies one or more virtual machines (VM) that have a working operating system (OS) as well as a predefined set of software development tools. As for the wrong answers, Software as a Service (SaaS) supplies a predefined software application, but typically with no ability to then later install your own applications. IaaS (Infrastructure as a Service) supplies one or more working VMs, optionally with an OS installed, so it could be used for software development, but the developer would have to install a variety of development tools, making IaaS less useful than a PaaS service. Finally, SLBaaS (Server Load Balancing as a Service) can be offered as a cloud service, but it is not a general service in which customers get access to VMs on which they can then install their own applications.

1. A Network Management Station (NMS) is using SNMP to manage some Cisco routers and switches with SNMPv2c. Which of the following answers most accurately describes how the SNMP agent on a router authenticates any SNMP Get requests received from the NMS? a. Using a username and hashed version of a password b. Using either the read-write or read-only community string c. Using only the read-write community string d. Using only the read-only community string

1. B. SNMPv1 and SNMPv2c use community strings to authenticate Get and Set messages from an NMS. The agent defines a read-only community and can define a readwrite community as well. Get requests, which read information, will be accepted if the NMS sends either the read-only or the read-write community with those requests.

1. In the cabling for a leased line, which of the following usually connects to a four-wire line provided by a telco? a. Router serial interface without internal CSU/DSU b. CSU/DSU c. Router serial interface with internal transceiver d. Switch serial interface

1. B. The four-wire circuit cable supplied by the telco connects to the device acting as the CSU/DSU. That can be an external CSU/DSU or a CSU/DSU integrated into a router serial interface card. LAN switches do not have serial interfaces, and router serial interfaces do not have transceivers.

1. Which of the following network commands, following the command router ospf 1, tells this router to start using OSPF on interfaces whose IP addresses are 10.1.1.1, 10.1.100.1, and 10.1.120.1? a. network 10.0.0.0 255.0.0.0 area 0 b. network 10.0.0.0 0.255.255.255 area 0 c. network 10.0.0.1 0.0.0.255 area 0 d. network 10.0.0.1 0.0.255.255 area 0

1. B. The network 10.0.0.0 0.255.255.255 area 0 command works, because it matches all interfaces whose first octet is 10. The rest of the commands match as follows: all addresses that end with 0.0.0 (wildcard mask 255.0.0.0); all addresses that begin with 10.0.0 (wildcard mask 0.0.0.255); and all addresses that begin with 10.0 (wildcard mask 0.0.255.255).

1. Which of the following are differences between OSPFv2 and OSPFv3? (Choose two answers.) a. OSPFv2 uses neighbor relationships, while OSPFv3 does not. b. OSPFv2 uses an SPF algorithm, while OSPFv3 uses the DUAL algorithm. c. OSPFv2 uses LSAs, while OSPFv3 uses LSAs but with differences. d. OSPFv2 is a link-state protocol, while OSPFv3 is an advanced distance vector protocol. e. OSPFv2 can advertise IPv4 routes, while OSPFv3 can advertise both IPv4 and IPv6 routes.

1. C, E. OSPFv2 and OSPFv3 are both link-state protocols that use the SPF algorithm to calculate the best routes. They both use the concept of being enabled on an interface, and then discovering neighbors on those interfaces by using Hello messages. One key difference between the two is that OSPFv3 introduces some new link-state advertisement (LSA) types. The other key difference, of course, is that OSPFv3 supports the advertisement of IPv6 routes.

1. An enterprise uses a dual-stack model of deployment for IPv4 and IPv6, using EIGRP as the routing protocol for both. Router R1 has IPv4 and IPv6 addresses on its G0/0 and S0/0/0 interfaces only, with EIGRP for IPv4 and EIGRP for IPv6 enabled on both interfaces. Which of the following answers is a valid way to configure R1 so that it enables EIGRP for IPv6 on the exact same interfaces as EIGRP for IPv4 in this case? a. Adding the dual-stack all-interfaces router subcommand for EIGRP for IPv6 b. Adding the dual-stack interface subcommand to interfaces G0/0 and S0/0/0 c. Adding the ipv6 eigrp asn interface subcommand to interfaces G0/0 and S0/0/0 d. Adding the dual-stack all-interfaces router subcommand for EIGRP for IPv4

1. C. IOS supports no direct method for IOS to decide which interfaces have EIGRP for IPv4 enabled, and then automatically enable EIGRP for IPv6 on those same interfaces. The correct answer shows how to enable EIGRP for IPv6 directly on the two interfaces in question. The three incorrect answers also list nonexistent commands.

1. IPv6 access control lists are configured in which of the following ways? a. Using ACL numbers 2300-2499 b. Using ACL numbers 3000-3999 c. Using ACL names to uniquely identify each ACL d. Using subinterfaces on the physical router's interface descriptor block

1. C. IPv6 ACLs are names and do not use ACL numbers.

1. Which of the following routing protocols is considered to use link-state logic? a. RIPv1 b. RIPv2 c. EIGRP d. OSPF

1. D. Both versions of RIP use distance vector logic, and EIGRP uses a different kind of logic, characterized either as advanced distance vector or a balanced hybrid.

1. With IEEE 802.1x, which role does a LAN switch typically play? a. Authentication server b. Supplicant c. Translator d. Authenticator

1. D. Of the four answers, the answer "translator" is not an 802.1x role, but the other three are 802.1x roles. The device that is connecting to the network and would like to gain access is the supplicant. The AAA server that can check its list of usernames and passwords is called the authentication server. The switch, which does in some way translate between message formats for this process, plays the role that 802.1x defines as authenticator.

1. Which of the following distance vector features prevents routing loops by causing the routing protocol to advertise only a subset of known routes, as opposed to the full routing table, under normal stable conditions? a. Route poisoning b. Poison reverse c. DUAL d. Split horizon

1. D. Split horizon causes a router to not advertise a route out of the same interface on which the router was learned. It also causes the router to not advertise about the connected route on an interface in updates sent out that interface.

1. R1 and R2 attach to the same Ethernet VLAN, with subnet 10.1.19.0/25, with addresses 10.1.19.1 and 10.1.19.2, respectively, configured with the ip address interface subcommand. Host A refers to 10.1.19.1 as its default router, and host B refers to 10.1.19.2 as its default router. The routers do not use an FHRP. Which of the following is a problem for this LAN? a. The design breaks IPv4 addressing rules, because two routers cannot connect to the same LAN subnet. b. If one router fails, neither host can send packets off-subnet. c. If one router fails, both hosts will use the one remaining router as a default router. d. If one router fails, the host that uses that router as a default router cannot send packets off-subnet.

1. D. With this design, but no FHRP, host A can send packets off-subnet as long as connectivity exists from host A to R1. Similarly, host B can send packets off-subnet as long as host B has connectivity to router R2. Both routers can attach to the same LAN subnet, and basically ignore each other in relation to their roles as default router, because they do not use an FHRP option. When either router fails, the hosts using that router as default router have no means by which to fail over.

1. Which of the following fields cannot be compared based on an extended IP ACL? (Choose two answers.) a. Protocol b. Source IP address c. Destination IP address d. TOS byte e. URL f. Filename for FTP transfers

1. E and F. Extended ACLs can look at the Layer 3 (IP) and Layer 4 (TCP, UDP) headers and a few others, but not any application layer information. Named extended ACLs can look for the same fields as numbered extended ACLs.

2. Which of the following answers list a valid number that can be used with standard numbered IP ACLs? (Choose two answers.) a. 1987 b. 2187 c. 187 d. 87

2. A and D. The range of valid ACL numbers for standard numbered IP ACLs is 1-99 and 1300-1999, inclusive.

2. Which of the following access-list commands permit packets going from host 10.1.1.1 to all web servers whose IP addresses begin with 172.16.5? (Choose two answers.) a. access-list 101 permit tcp host 10.1.1.1 172.16.5.0 0.0.0.255 eq www b. access-list 1951 permit ip host 10.1.1.1 172.16.5.0 0.0.0.255 eq www c. access-list 2523 permit ip host 10.1.1.1 eq www 172.16.5.0 0.0.0.255 d. access-list 2523 permit tcp host 10.1.1.1 eq www 172.16.5.0 0.0.0.255 e. access-list 2523 permit tcp host 10.1.1.1 172.16.5.0 0.0.0.255 eq www

2. A and E. The correct range of ACL numbers for extended IP access lists is 100 to 199 and 2000 to 2699. The answers that list the eq www parameter after 10.1.1.1 match the source port number, and the packets are going toward the web server, not away from it.

2. Two routers connect with a serial link, each using its S0/0/0 interface. The link is currently working using PPP. The network engineer wants to migrate to use the Cisco-proprietary HDLC that includes a protocol type field. Which of the following commands can be used to migrate to HDLC successfully? (Choose two answers.) a. encapsulation hdlc b. encapsulation cisco-hdlc c. no encapsulation ppp d. encapsulation-type auto

2. A, C. The encapsulation hdlc command sets the interface encapsulation (datalink protocol) to HDLC. In addition, because Cisco routers default to use the Cisco-proprietary HDLC on serial interfaces, removing the use of PPP with the no encapsulation ppp command also works. The other two answers list commands that do not exist in IOS.

2. A router has been configured with the global command snmp-server community textvalue1 RO textvalue2. Which of the following statements are true about the meaning of this command? (Choose two answers.) a. The router's read-only community is textvalue1. b. The router's read-only community is textvalue2. c. The router filters incoming SNMP messages using IPv4 ACL textvalue2. d. The router filters outgoing SNMP messages using IPv4 ACL textvalue2.

2. A, C. The first parameter after the community keyword defines the community value. At the end of the command, if a text value is listed but without an ipv6 keyword, the text value is the name of an IPv4 ACL. The ACL (textvalue2 in this case) filters incoming SNMP messages received by the SNMP agent on the device.

2. An engineer configures a point-to-point GRE tunnel between two Cisco routers, called A and B. The routers use public IP addresses assigned by ISPs, and private addresses from network 10.0.0.0. Which of the following answers accurately describes where the addresses could be referenced in the GRE configuration? a. Router A's private address on an ip address command on Router A's tunnel interface b. Router A's private address on a tunnel destination command on Router B c. Router B's public address on a tunnel source command on Router A d. Router B's public address on an ip address command on Router B's tunnel interface

2. A. GRE tunnels that use private IP addresses on the tunnel and then use the Internet between the two routers need to configure references to both the private and public IP addresses. First, each router's tunnel interface has an ip address command that refers to the local router's private IP address. Additionally, each router configures a tunnel destination and tunnel source that refer to the public IP address of the other router (tunnel destination) and the local router (tunnel source). Two answers refer to Router A's private address. Per the first paragraph of this explanation, that address would be configured on a tunnel interface with an ip address command, on Router A, making one of those two answers correct. Private addresses would not be configured as the tunnel source or destination, making the other answer that mentions Router A's private address incorrect. Two answers refer to Router B's public address. Per the first paragraph of this explanation, that address would only be configured as a tunnel source or tunnel destination, and not with the ip address command. That fact makes one of the answers incorrect. Next, Router B's public IP address would be listed as the tunnel source on Router B, and the tunnel destination on Router A. The final (incorrect) answer suggests that Router B's public address would be configured as the tunnel source, but on Router A, which would be an incorrect setting.

2. Which of the following cloud services is most likely to be purchased and then used to later install your own software applications? a. IaaS b. PaaS c. SaaS d. SLBaaS

2. A. IaaS (Infrastructure as a Service) supplies one or more working virtual machines (VM), optionally with an OS installed, as a place where you can then customize the systems by installing your own applications. Software as a Service (SaaS) supplies a predefined software application, but typically with no ability to then later install your own applications. Platform as a Service (PaaS) could be used to install your own application, because PaaS does supply one or more VMs, but it is most likely used as a software development environment, a service designed specifically to be used for development, with VMs that include various tools that are useful for software development. Finally, SLBaaS (Server Load Balancing as a Service) can be offered as a cloud service, but it is not a general service in which customers get access to VMs on which they can then install their own applications.

2. Which of the following is the most likely technology used for an access link to a Metro Ethernet service? a. 100Base-LX10 b. High-speed TDM (for example, T3, E3) c. MPLS d. 100Base-T

2. A. Metro Ethernet uses Ethernet access links of various types. Time-division multiplexing (TDM) links such as serial links, even higher-speed links like T3 and E3, do not use Ethernet protocols, and are less likely to be used. MPLS is a WAN technology that creates a Layer 3 service. Two answers refer to Ethernet standards usable as the physical access link for a Metro Ethernet service. However, 100Base-T supports cable lengths of only 100 meters, so it is less likely to be used as a Metro Ethernet access link in comparison to 100Base- LX10, which supports lengths of 10 km.

2. Which of the following network commands, following the command router ospf 1, tells this router to start using OSPF on interfaces whose IP addresses are 10.1.1.1, 10.1.100.1, and 10.1.120.1? a. network 10.1.0.0 0.0.255.255 area 0 b. network 10.0.0.0 0.255.255.0 area 0 c. network 10.1.1.0 0.x.1x.0 area 0 d. network 10.1.1.0 255.0.0.0 area 0 e. network 10.0.0.0 255.0.0.0 area 0

2. A. The network 10.1.0.0 0.0.255.255 area 0 command matches all IP addresses that begin with 10.1, enabling OSPF in area 0 on all interfaces. The answer with wildcard mask 0.255.255.0 is illegal, because it represents more than one string of binary 0s separated by binary 1s. The answer with x's is syntactically incorrect. The answer with wildcard mask 255.0.0.0 means "Match all addresses whose last three octets are 0.0.0," so none of the three interfaces are matched.

2. Which of the following configuration settings does not have a separate IPv4/EIGRP for IPv4 and IPv6/EIGRP for IPv6 setting, instead using one setting that both EIGRP for IPv4 and EIGRP for IPv6 use? a. Interface bandwidth b. Hello timer c. Variance d. Maximum paths

2. A. The three incorrect answers have separate settings. The Hello timer can be set with the ip hello-timer eigrp asn timer command for EIGRP for IPv4, and with the IP the ipv6 hello-timer eigrp asn timer command for EIGRP for IPv6. The variance and maximum-paths commands, router subcommands, have the same syntax for both routing protocols but are set separately for EIGRP for IPv4 and EIGRP for IPv6. The interface bandwidth and delay commands impact both EIGRP for IPv4 and EIGRP for IPv6.

2. Router R1 has a router-on-a-stick (ROAS) configuration with two subinterfaces of interface G0/1: G0/1.1 and G0/1.2. Physical interface G0/1 is currently in a down/down state. The network engineer then configures a shutdown command when in interface configuration mode for G0/1.1, and a no shutdown command when in interface configuration mode for G0/1.2. Which answers are correct about the interface state for the subinterfaces? (Choose two answers.) a. G0/1.1 will be in a down/down state. b. G0/1.2 will be in a down/down state. c. G0/1.1 will be in an administratively down state. d. G0/1.2 will be in an up/up state.

2. B, C. Subinterface G0/1.1 must be in an administratively down state due to the shutdown command being issued on that subinterface. For subinterface G0/1.2, its status cannot be administratively down, because of the no shutdown command. G0/1.2's state will then track to the state of the underlying physical interface. With a physical interface state of down/down, subinterface G0/1.2 will be in a down/down state in this case.

2. Which of the following QoS marking fields could remain with a packet while being sent through four different routers, over different LAN and WAN links? (Choose two answers.) a. CoS b. IPP c. DSCP d. MPLS EXP

2. B, C. The Class of Service (CoS) field exists in the 802.1Q header, so it would be used only on trunks, and it would be stripped of the incoming data link header by any router in the path. The MPLS EXP bits exist as the packet crosses the MPLS network only. The other two fields, IP Precedence (IPP) and Differentiated Services Code Point (DSCP), exist in the IP header, and would flow from source host to destination host.

2. Examine the following extract from the show spanning-tree command on a Cisco switch: Bridge ID Priority 32771 (priority 32768 sys-id-ext 3) Address 0019.e86a.6f80 Which of the following answers is true about the switch on which this command output was gathered? a. The information is about the STP instance for VLAN 1. b. The information is about the STP instance for VLAN 3. c. The command output confi rms that this switch cannot possibly be the root switch. d. The command output confi rms that this switch is currently the root switch.

2. B. Cisco switches use the extended system ID format for BIDs by default, in which the priority field is broken down into a base priority value (32,768 in this case) plus the VLAN ID. The priority of this switch allows it to be capable of being the root switch, but the command output does not supply enough information to know whether this switch is currently root.

2. An engineer wants to set the OSPFv3 router ID for Router R1. Which of the following answers could affect R1's choice of OSPFv3 router ID? a. The ipv6 address command on interface Gigabit0/0 b. The ip address command on interface Serial0/0/1 c. The ospf router-id command in OSPFv3 configuration mode d. The ipv6 address command on interface loopback2

2. B. OSPFv3 uses the exact same rules for choosing its router ID (RID) as does OSPFv2, even choosing the 32-bit RID value based on IPv4 addresses, and not based on the IPv6 addresses. The two answers that mention the ipv6 address command have no impact on the OSPFv3 RID. For the other incorrect answer, the ospf router-id command does not exist; instead, the command is simply the router-id command. Only the answer with the ip address interface subcommand can impact a router's choice of OSPFv3 RID.

2. Which of the following routing protocols use a metric that is, by default, at least partially affected by link bandwidth? (Choose two answers.) a. RIPv1 b. RIPv2 c. EIGRP d. OSPF

2. C, D. Both versions of RIP use the same hop-count metric, neither of which is affected by link bandwidth. EIGRP's metric, by default, is calculated based on bandwidth and delay. OSPF's metric is a sum of outgoing interfaces costs, with those costs (by default) based on interface bandwidth.

2. Which of the following are transitory IEEE 802.1D port states used only during the process of STP convergence? (Choose two answers.) a. Blocking b. Forwarding c. Listening d. Learning e. Discarding

2. C, D. Listening and learning are transitory port states, used only when moving from the blocking to the forwarding state. Discarding is not an 802.1D STP port state. Forwarding and blocking are stable states.

2. Routers R1 and R2 attach to the same VLAN with IP addresses 10.0.0.1 and 10.0.0.2, respectively. R1 is configured with the commands router eigrp 99 and network 10.0.0.0. Which of the following commands might be part of a working EIGRP configuration on R2 that ensures that the two routers become neighbors and exchange routes? (Choose two answers.) a. network 10 b. network 10.0.0.1 0.0.0.0 c. network 10.0.0.2 0.0.0.0 d. network 10.0.0.0

2. C, D. The EIGRP network 10.0.0.2 0.0.0.0 command exactly matches the interface with address 10.0.0.2 because of the wildcard mask, enabling EIGRP on that interface. The EIGRP ASN value must match on both routers. The network 10.0.0.1 0.0.0.0 command exactly matches the address on R1, but the network command needs to match addresses on the local router, and these commands should exist on Router R2. The network 10 command is syntactically incorrect; the entire classful network must be configured.

2. Which of the following features is true of eBGP but not iBGP? a. Connects routers in the same ASN b. Uses TCP c. Exchanges routes between an ISP and an enterprise d. None of the other answers is correct

2. C. External BGP, or eBGP, refers to BGP as used between two autonomous systems (as identified by using different autonomous system numbers). Both Interior BGP (iBGP) and eBGP use TCP. Only iBGP connects to other routers in the same ASN. The one answer that describes what eBGP does, but that iBGP does not, is that eBGP exchanges routes between an enterprise and an ISP, the two of which use different ASNs.

2. Which of the following statements is true about IPv6 ACLs? a. Cisco router interfaces can only have one IPv4 or one IPv6 ACLs applied in only one direction. b. Cisco router interfaces can have either an IPv4 or IPv6 ACL applied, but in both directions. c. Cisco router interfaces can have both IPv4 and IPv6 ACLs applied inbound and outbound on a single interface. d. Cisco router interfaces can have either an IPv4 or an IPv6 ACL applied, but only in one direction.

2. C. IPv4 ACLs can be applied to a routed interface in the inbound and outbound direction. Similarly, IPv6 ACLs can be applied to a routed interface in the inbound and outbound direction. Therefore, it is possible to have a routed interface with four ACLs applied: two IPv4 ACLs (one inbound and one outbound) and two IPv6 ACLs (one inbound and one outbound).

2. Which of the following answers is true of TACACS+ but not true of RADIUS? a. The protocol encrypts the password for transmission. b. Uses UDP as the transport protocol. c. Supports ability to authorize different users to use different subsets of CLI commands. d. Defined by an RFC.

2. C. TACACS+, defined by Cisco, uses TCP as its transport protocol. Cisco defines TACACS+ with an ability to authorize users for different subsets of CLI commands, whereas RADIUS does not. Both RADIUS and TACACS+ encrypt the passwords before transmitting them.

2. A router uses EIGRP to learn routes and adds those to the IPv4 routing table. That action is an action that occurs as part of which plane of the router? a. Data plane b. Management plane c. Control plane d. Table plane

2. C. The control plane includes all networking device actions that create the information used by the data plane when processing messages. The control plane includes functions like IP routing protocols and Spanning Tree Protocol (STP). The term table plane is not used in networking. The management plane and data plane are not concerned with collecting the information that the data plane then uses.

2. R1 and R2 attach to the same Ethernet VLAN, with subnet 10.1.19.0/25, with addresses 10.1.19.1 and 10.1.19.2, respectively, configured with the ip address interface subcommand. The routers use an FHRP. Host A and host B attach to the same LAN and have correct default router settings per the FHRP configuration. Which of the following statements is true for this LAN? a. The design breaks IPv4 addressing rules, because two routers cannot connect to the same LAN subnet. b. If one router fails, neither host can send packets off-subnet. c. If one router fails, both hosts will use the one remaining router as a default router. d. If one router fails, only one of the two hosts will still be able to send packets offsubnet.

2. C. The use of an FHRP in this design purposefully allows either router to fail and still support off-subnet traffic from all hosts in the subnet. Both routers can attach to the same LAN subnet per IPv4 addressing rules.

2. An engineer plans to connect three switches (SW1, SW2, and SW3) in a lab. Before connecting the switches, he starts by configuring all three switches as VTP servers, with matching VTP domain name and password. He then configures some VLANs on each switch so that switch SW3 has a revision number of 10, switch SW2 has a revision number of 6, and switch SW1 has a revision number of 8. Only then does the engineer connect the switches with trunks: first SW1 to SW2, then SW2 to SW3, and then SW3 to SW1. Switch SW1 is elected the STP root switch in VLAN 1. Which answer most accurately states which VLAN configuration database is used, and why? a. All use switch SW1's database because it has the highest revision number between the fi rst two connected switches. b. All use switch SW1's database because VTP uses the same election logic as STP. c. All use SW3's database because SW3 has the highest revision number. d. All use SW2's database because SW2 has the lowest revision number.

2. C. When any two switches connect with a trunk, and both use VTP in either client or server mode, they exchange VTP messages. Then the switch with the lower revision number updates its VLAN configuration database to match the VLAN configuration database with the higher revision number. In this case, with all three switches eventually connecting to each other through some path with trunks, the highest revision number database will win. The STP election process has nothing to do with the choices made by VTP.

2. Imagine a switch with three configured VLANs. How many IP subnets are required, assuming that all hosts in all VLANs want to use TCP/IP? a. 0 b. 1 c. 2 d. 3 e. You cannot tell from the information provided.

2. D. Although a subnet and a VLAN are not equivalent concepts, the devices in one VLAN are typically in the same IP subnet and vice versa.

2. Which of the following distance vector features prevents routing loops by advertising an infinite metric route when a route fails? a. Dijkstra SPF b. DUAL c. Split horizon d. Route poisoning

2. D. Route poisoning means advertising the failed route with an "infinite" metric, as opposed to simply ceasing to advertise the route. Of the incorrect answers, SPF defines how link-state protocols calculate and choose routes; DUAL defines how EIGRP does some of its processing to find replacement routes; and split horizon limits which routes a router advertises to help avoid routing loops.

3. Which of the following are available methods of classifying packets in DiffServ on Cisco routers? (Choose three answers.) a. Matching the IP DSCP field b. Matching the 802.1p CoS field c. Matching fields with an extended IP ACL d. Matching the SNMP Location variable

3. A, B, C. In general, matching a packet with DiffServ relies on a comparison to something inside the message itself. The 802.1p CoS field exists in the data link header on VLAN trunks; the IP DSCP field exists in the IP header; and extended ACLs check fields in message headers. The SNMP Location variable does not flow inside individual packets, but is a value that can be requested from a device.

3. An engineer hears about DHCP snooping and decides to implement it. The network includes devices that act primarily as Layer 2 switches, multilayer switches (that is, they perform both Layer 2 and Layer 3 switching), and routers. Which of the following are the devices on which DHCP snooping could be implemented? (Choose two answers.) a. Layer 2 switches b. Routers c. Multilayer switches d. A LAN hub

3. A, C. DHCP snooping must be implemented on a device that does Layer 2 switching. The DHCP snooping function needs to examine DHCP messages that flow between devices within the same broadcast domain (VLAN). Layer 2 switches perform that function, as well as multilayer switches. Because a router performs only Layer 3 forwarding (that is, routing), and does not forward messages between devices in the same VLAN, a router does not provide a good platform to implement DHCP snooping (and is not even a feature of Cisco IOS on routers).

3. An enterprise uses a Metro Ethernet WAN with an Ethernet LAN (E-LAN) service, with the company headquarters plus ten remote sites connected to the service. The enterprise uses EIGRP at all sites, with one router connected to the service from each site. Which of the following are true about the Layer 3 details most likely used with this service and design? (Choose two answers.) a. The WAN uses one IP subnet. b. The WAN uses ten or more IP subnets. c. A remote site router would have one EIGRP neighbor. d. A remote site router would have ten EIGRP neighbors.

3. A, D. An E-LAN service is one in which the Metro Ethernet service acts as if the WAN were a single Ethernet switch, so that each device can communicate directly to every other device. As a result, the routers sit in the same subnet. With one headquarters router and ten remote sites, each router will have ten EIGRP neighbors.

3. A switch's G0/1 interface, a trunk that supports VLANs 1-10, has autonegotiated a speed of 100 Mbps. The switch currently has all default settings for STP. Which of the following actions results in the switch using an STP cost of 19 for that interface in VLAN 3? (Choose two answers.) a. spanning-tree cost 19 b. spanning-tree port-cost 19 c. spanning-tree vlan 3 port-cost 19 d. Adding no confi guration

3. A, D. The spanning-tree cost 19 command sets the cost for all VLANs on that interface unless the cost is set by a spanning-tree cost command that lists the VLAN ID. The two commands with a port-cost parameter are incorrect; the correct keyword is simply cost. Finally, Cisco switches choose the default cost based on the current speed, not the interface's fastest possible speed. So, this interface, running at 100 Mbps, already defaults to the IEEE default cost for 100 Mbps, or 19.

3. An engineer compares the output of the show vtp status command on two neighboring switches. One switch, SW1, acts as VTP server, while the other, SW2, acts as a VTP client. What items in the command output confirm that synchronization has completed? (Choose two answers.) a. Both list the same "last updater" IP address and timestamp. b. Both list the neighbor's MAC address and the word "synchronized." c. SW2 (the client) lists the phrase "synchronized with server." d. Both list the same confi guration revision number.

3. A, D. VTP synchronization causes two neighboring VTP server and/or client switches to update the switch with the configuration database that has the lower revision number to use the newer database from the neighbor that has the higher revision number. Once completed, the show vtp status command on both switches will list the same revision number. Because both use the same configuration database, both will list the same information about the "last updater," which is this command's method of referring to the VTP server that last changed the configuration. The two incorrect answers list text that does not occur in the output of the show vtp status command.

3. Which of the following commands list the OSPF neighbors off interface serial 0/0? (Choose two answers.) a. show ip ospf neighbor b. show ip ospf interface brief c. show ip neighbor d. show ip interface e. show ip ospf neighbor serial 0/0

3. A, E. Of the three wrong answers, two are real commands that simply do not list the OSPF neighbors. show ip ospf interface brief lists interfaces on which OSPF is enabled, but does not list neighbors. show ip interface lists IPv4 details about interfaces, but none related to OSPF. One incorrect answer, show ip neighbor, is not a valid IOS command.

3. An enterprise plans to start using a public cloud service, and is considering different WAN options. The answers list four options under consideration. Which one option has the most issues if the company chooses one cloud provider but then later wants to change to use a different cloud provider instead? a. Using private WAN connections directly to the cloud provider b. Using an Internet connection without VPN c. Using an intercloud exchange d. Using an Internet connection with VPN

3. A. Both options that use the Internet allow for easier migration because public cloud providers typically provide easy access over the Internet. An intercloud exchange is a purpose-built WAN service that connects to enterprises as well as most public cloud providers, with the advantage of making the cloud migration process easier. The one correct answer—the worst option in terms of being prepared for migrating to a new cloud provider—is to use a private WAN connection to one cloud provider. While useful in other ways, migrating when using this strategy would require installing a new private WAN connection to the new cloud provider.

3. Routers A and B use EIGRP. How does router A watch for the status of router B so that router A can react if router B fails? a. By using EIGRP Hello messages, with A needing to receive periodic Hello messages to believe B is still working. b. By using EIGRP update messages, with A needing to receive periodic update messages to believe B is still working. c. Using a periodic ping of B's IP address based on the EIGRP neighbor timer. d. None of the other answers are correct.

3. A. EIGRP separates the function of monitoring neighbor state into the Hello message process, relying on the receipt of a Hello message. If a router does not receive an EIGRP Hello within the configured EIGRP hold time, the local router believes the neighbor has failed.

3. Which of the following interior routing protocols support VLSM? (Choose three answers.) a. RIPv1 b. RIPv2 c. EIGRP d. OSPF

3. B, C, D. Of the listed routing protocols, only the old RIP Version 1 (RIP-1) protocol does not support variable-length subnet masks (VLSM).

3. Consider the routes advertised over a typical single-homed Internet edge connection that uses eBGP. Which of the following answers describe a route typically advertised by eBGP in this case? (Choose two answers.) a. A default route advertised by the enterprise to the ISP b. A route for the enterprise's public IPv4 address block to the ISP c. A route for the enterprise's private IPv4 address block to the ISP d. A default route advertised by the ISP to the enterprise

3. B, D. The enterprise typically advertises its public IPv4 address block to the ISP. There is no need to advertise its private IP address block, because Internet routers will not route packets to private IPv4 networks anyway. As for default routes, the enterprise can benefit from using a default route as advertised by the ISP, but not vice versa.

3. Switch SW1 sends a frame to switch SW2 using 802.1Q trunking. Which of the answers describes how SW1 changes or adds to the Ethernet frame before forwarding the frame to SW2? a. Inserts a 4-byte header and does change the MAC addresses b. Inserts a 4-byte header and does not change the MAC addresses c. Encapsulates the original frame behind an entirely new Ethernet header d. None of the other answers are correct.

3. B. 802.1Q defines a 4-byte header, inserted after the original frame's destination and source MAC address fields. The insertion of this header does not change the original frame's source or destination address. The header itself

3. Router R1 has a Serial0/0/0 interface with address 2001:1:1:1::1/64, and a G0/0 interface with address 2001:2:2:2::1/64. The OSPFv3 process uses process ID 1. Which of the following OSPFv3 configuration commands enables OSPFv3 on R1's G0/0 interface and places it into area 0? a. A network 2001:1:1:1::/64 1 area 0 command in router configuration mode b. An ipv6 ospf 1 area 0 command in G0/0 interface configuration mode c. A network 2001:1:1:1::/64 1 area 0 command in router configuration mode d. An ospf 1 area 0 command in G0/0 interface configuration mode

3. B. OSPFv3 does not use a network command in OSPFv3 router configuration mode, ruling out two of the answers. It does use an interface subcommand that both refers to the OSPFv3 by process ID and defines the area number. The correct answer lists that interface subcommand with the correct syntax.

3. A network uses an SDN architecture with switches and a centralized controller. Which of the following terms describes a function or functions expected to be found on the switches but not on the controller? a. A Northbound Interface b. A Southbound Interface c. Data plane functions d. Control plane functions

3. C. Although many variations of SDN architectures exist, they typically use a centralized controller. That controller may centralize some or even all control plane functions in the controller. However, the data plane function of receiving messages, matching them based on header fields, taking actions (like making a forwarding decision), and forwarding the message still happens on the network elements (switches) and not on the controller. For the incorrect answers, the control plane functions may all happen on the controller, or some may happen on the controller, and some on the switches. The Northbound and Southbound Interfaces are API interfaces on the controller, not on the switches.

3. R1 and R2 attach to the same Ethernet VLAN, with subnet 10.1.19.0/25, with addresses 10.1.19.1 and 10.1.19.2, respectively, configured with the ip address interface subcommand. The routers use HSRP. The network engineer prefers to have R1 be the default router when both R1 and R2 are up. Which of the following is the likely default router setting for hosts in this subnet? a. 10.1.19.1 b. 10.1.19.2 c. Another IP address in subnet 10.1.19.0/25 other than 10.1.19.1 and 10.1.19.2 d. A hostname that the FHRP mini-DNS will initially point to 10.1.19.1

3. C. HSRP uses a virtual IP address. The virtual IP address comes from the same subnet as the routers' LAN interfaces, but is a different IP address than the router addresses configured with the ip address interface subcommand. As a result, the hosts will not point to 10.1.19.1 or 10.1.19.2 in this design. The other wrong answer lists an idea of using Domain Name System (DNS) to direct hosts to the right default router; although this idea exists in some other forms of network load balancing, it is not a part of any of the three FHRP protocols.

3. Which of the following PPP authentication protocols authenticates a device on the other end of a link without sending any password information in clear text? a. MD5 b. PAP c. CHAP d. DES

3. C. Of the possible answers, only PAP and CHAP are PPP authentication protocols. PAP sends the password as clear text between the two devices.

3. A Layer 3 switch has been configured to route IP packets between VLANs 1, 2, and 3 using SVIs, which connect to subnets 172.20.1.0/25, 172.20.2.0/25, and 172.20.3.0/25, respectively. The engineer issues a show ip route connected command on the Layer 3 switch, listing the connected routes. Which of the following answers lists a piece of information that should be in at least one of the routes? a. Interface Gigabit Ethernet 0/0.3 b. Next-hop router 172.20.2.1 c. Interface VLAN 2 d. Mask 255.255.255.0

3. C. The configuration of the Layer 3 switch's routing feature uses VLAN interfaces. The VLAN interface numbers must match the associated VLAN ID, so with VLANs 1, 2, and 3 in use, the switch will configure interface vlan 1, interface vlan 2 (which is the correct answer), and interface vlan 3. The matching connected routes, like all connected IP routes, will list the VLAN interfaces. As for the incorrect answers, a list of connected routes will not list any next-hop IP addresses. Each route will list an outgoing interface, but the outgoing interface will not be a physical interface, but rather a VLAN interface, because the question states that the configuration uses SVIs. Finally, all the listed subnets have a /25 mask, which is 255.255.255.128, so none of the routes will list a 255.255.255.0 mask.

3. Which of the following bridge IDs wins election as root, assuming that the switches with these bridge IDs are in the same network? a. 32769:0200.1111.1111 b. 32769:0200.2222.2222 c. 4097:0200.1111.1111 d. 4097:0200.2222.2222 e. 40961:0200.1111.1111

3. C. The smallest numeric bridge ID wins the election.

3. An enterprise uses a site-to-site GRE tunnel that runs over the Internet between two routers (R1 and R2). R1 uses tunnel interface 22. The tunnel has a source of 1.1.1.1 and a destination of 2.2.2.2. All the answers list facts that could be true, but which of the following must be true when Router R1's tunnel 22 is in an up/up state? a. 2.2.2.2 is pingable from Router R1. b. 1.1.1.1 is pingable from Router R2. c. R1 has a working (up/up) interface with address 1.1.1.1. d. R2 has a working (up/up) interface with address 2.2.2.2.

3. C. To justify the correct answer: R1's source address for the tunnel must be an address on R1, on an interface in an up/up state, or the tunnel will fail to an up/down state. For the two answers that mention ping, GRE tunnels do local checks to determine the interface status, but they do not check connectivity with pings. So, a tunnel interface can reach an up/up state even though a ping to the destination of the tunnel would currently fail. (The router must have a route for forwarding packets to the destination; just no guarantee that the packet would arrive.) In this case, R1 would have a route that matches destination 2.2.2.2, R2 would have a route that matches 1.1.1.1, and the tunnel interface could be up/up even though a ping would currently fail for other reasons. Finally, for the tunnel to work correctly, and forward traffic, R2 would need a working interface with address 2.2.2.2. However, R1's tunnel interface state is independent from whether R2's interfaces are currently up or down.

3. Which of the following wildcard masks is most useful for matching all IP packets in subnet 10.1.128.0, mask 255.255.255.0? a. 0.0.0.0 b. 0.0.0.31 c. 0.0.0.240 d. 0.0.0.255 e. 0.0.15.0 f. 0.0.248.255

3. D. 0.0.0.255 matches all packets that have the same first three octets. This is useful when you want to match a subnet in which the subnet part comprises the first three octets, as in this case.

3. Which of the following IPv6 ACL entries would match and permit IPv6 packets coming from the Internet destined for the 2001:0db8:1111:0001:0000:0000:0000:0000 prefix with a 64-bit prefix length? a. permit ipv6 any 2001:db8:1111:1::1 b. permit ipv6 2001:db8:1111:1::/64 any c. permit ipv6 any 2001:db8:1111:1::1/128 d. permit ipv6 any 2001:db8:1111:1::/64

3. D. IPv6 ACLs use the any keyword to represent all possible IPv6 address (as in the whole Internet). The 2001:db8:1111:1::/64 prefix uses this syntax to represent any node on the network that has those first four hextets with the "/64" prefix length notation.

3. In the show ip route command, what code designation implies that a route was learned with EIGRP? a. E b. I c. G d. D

3. D. RIP uses R, and OSPF uses O, but EIGRP uses D. The letter E was already in use by an old (and no longer used) routing protocol, so Cisco chose to use nearby letter D for EIGRP.

3. An enterprise uses a dual-stack model of deployment for IPv4 and IPv6, using EIGRP as the routing protocol for both. Router R1 has IPv4 and IPv6 addresses on its G0/0 and S0/0/0 interfaces only, with EIGRP for IPv4 and EIGRP for IPv6 enabled on both interfaces and the router ID explicitly set for both protocols. Comparing the EIGRP for IPv4 and EIGRP for IPv6 configuration, which of the following statements is true? a. The EIGRP for IPv6 configuration uses the router eigrp asn global command. b. Both protocols use the router-id router-id router subcommand. c. Both protocols use the network network-number router subcommand. d. The EIGRP for IPv6 configuration uses the ipv6 eigrp asn interface subcommand.

3. D. The EIGRP for IPv6 configuration would use ipv6 router eigrp asn, eigrp router-id router-id, and then, under each interface, ipv6 eigrp asn. EIGRP for IPv6 does not use the router eigrp asn command (it uses the ipv6 router eigrp asn command instead), and EIGRP for IPv6 also does not use the network command.

3. A router has been configured with the following command: snmp-server group one v3 auth write v1default. Which of the following answers lists a command that would correctly define a user to associate with this SNMPv3 group to correctly define security parameters to work with an SNMP manager? a. snmp-server user fred1 one v3 auth md5 pass1 priv des keyvalue1 b. snmp-server user fred2 v3 c. snmp-server user fred3 one v3 auth 3des pass1 d. snmp-server user fred4 one v3 auth sha pass1

3. D. To work correctly with an SNMP manager, the snmp-server user command must configure its parameters based on the security level in the referenced group as defined in the referenced snmp-server group command. In this case, the referenced snmp-server group command lists a security level of auth, so the snmp-server user command needs the auth keyword and associated parameters, but not the priv keyword and its associated parameters. Two answers are incorrect because they either do not include the auth keyword and associated parameters, or because it also includes the priv keyword. Of the two answers that include only the auth option, one is incorrect by referencing 3des as an authentication hash algorithm; this keyword refers to an encryption type that could follow the priv keyword, but it is invalid as an authentication option. The correct answer correctly lists sha as a valid authentication hash option, along with the userdefined password (pass1).

3. Which of the following access-list commands permits packets going to any web client from all web servers whose IP addresses begin with 172.16.5? a. access-list 101 permit tcp host 10.1.1.1 172.16.5.0 0.0.0.255 eq www b. access-list 1951 permit ip host 10.1.1.1 172.16.5.0 0.0.0.255 eq www c. access-list 2523 permit tcp any eq www 172.16.5.0 0.0.0.255 d. access-list 2523 permit tcp 172.16.5.0 0.0.0.255 eq www 172.16.5.0 0.0.0.255 e. access-list 2523 permit tcp 172.16.5.0 0.0.0.255 eq www any

3. E. Because the packet is going toward any web client, you need to check for the web server's port number as a source port. The client IP address range is not specified in the question, but the servers are, so the source address beginning with 172.16.5 is the correct answer.

4. In a router running a recent IOS version (at least version 15.0), an engineer needs to delete the second line in ACL 101, which currently has four commands configured. Which of the following options could be used? (Choose two answers.) a. Delete the entire ACL and reconfigure the three ACL statements that should remain in the ACL. b. Delete one line from the ACL using the no access-list... global command. c. Delete one line from the ACL by entering ACL configuration mode for the ACL and then deleting only the second line based on its sequence number. d. Delete the last three lines from the ACL from global configuration mode, and then add the last two statements back into the ACL.

4. A and C. Before IOS 12.3, numbered ACLs must be removed and then reconfigured to remove a line from the ACL. As of IOS 12.3, you can also use ACL configuration mode and sequence numbers to delete one ACL line at a time.

4. Imagine that you are told that switch 1 is configured with the dynamic auto parameter for trunking on its Fa0/5 interface, which is connected to switch 2. You have to configure switch 2. Which of the following settings for trunking could allow trunking to work? (Choose two answers.) a. trunk b. dynamic auto c. dynamic desirable d. access

4. A and C. The dynamic auto setting means that the switch can negotiate trunking, but it can only respond to negotiation messages, and it cannot initiate the negotiation process. So, the other switch must be configured to trunk or to initiate the negotiation process (based on being configured with the dynamic desirable option).

4. Which of the following affect the calculation of EIGRP metrics when all possible default values are used? (Choose two answers.) a. Bandwidth b. Delay c. Load d. Reliability e. MTU f. Hop count

4. A, B. EIGRP uses bandwidth and delay by default. Load and reliability can be added to the mix with configuration, but Cisco recommends against adding these to the metric calculation.

4. Switches SW1, SW2, SW3, and SW4 are configured as VTP server, client, transparent, and off, respectively, all using VTP version 1. A junior engineer has been told to try to configure the following two commands on each switch directly from the CLI: vlan 200 and vlan 2000. Which answers correctly state which commands will be rejected, on which switch? (Choose two answers.) a. vlan 2000 will be rejected on SW1 (VTP server). b. vlan 200 will be rejected on SW2 (VTP client). c. vlan 200 will be rejected on SW3 (VTP transparent). d. vlan 200 will be rejected on SW1 (VTP server).

4. A, B. One correct answer shows a vlan command being issued on a VTP client, which is not allowed. IOS actually rejects the vlan command when issued on a VTP client. The other correct answer relies on the fact that VTP version 1 (and 2) restricts VTP servers and clients to know of standard range VLANs only (VLANs 1-1005). As a result, the vlan 2000 command on a VTP server (switch SW1) would also be rejected. As for the two incorrect answers, the vlan 200 command would be accepted on a transparent mode switch. On the VTP server, that same vlan 200 command would be accepted, because VLAN ID 200 is inside the range of standard VLAN IDs.

4. An enterprise plans to start using a public cloud service, and is considering different WAN options. The answers list four options under consideration. Which options provide good security by keeping the data private while also providing good QoS services? (Choose two answers.) a. Using private WAN connections directly to the cloud provider b. Using an Internet connection without VPN c. Using an intercloud exchange d. Using an Internet connection with VPN

4. A, C. Private WAN options use technologies like Ethernet WAN and MPLS, both of which keep data private by their nature and which include QoS services. An intercloud exchange is a purpose-built WAN service that connects to enterprises as well as most public cloud providers, using the same kinds of private WAN technology with those same benefits. For the two incorrect answers, both use the Internet, so both cannot provide QoS services. The Internet VPN option does encrypt the data to keep it private.

4. Two routers have no initial configuration whatsoever. They are connected in a lab using a DTE cable connected to R1 and a DCE cable connected to R2, with the DTE and DCE cables then connected to each other. The engineer wants to create a working PPP link by configuring both routers. Which of the following commands are required in the R1 configuration for the link to reach a state in which R1 can ping R2's serial IP address, assuming that the physical back-to-back link physically works? (Choose two answers.) a. encapsulation ppp b. no encapsulation hdlc c. clock rate d. ip address

4. A, D. Both routers need an encapsulation ppp command, and both also need IP addresses before the ping will work. R1 does not need a clock rate command because R2 is connected to the DCE cable.

4. Routers R1 and R2, in two different ASNs, connect directly to each other over a WAN link, with the two routers in the same subnet. If using the IP addresses on that common link to define the eBGP neighbors, how many different BGP neighbor commands would be required on Router R1 to make the eBGP peer work to Router R2? (There is one answer.) a. 1 b. 2 c. 3 d. 4

4. A. For this scenario, each router would need a neighbor ip-address remote-as asn BGP subcommand, but no other neighbor commands. For example, if using ASNs 1 and 2, and link IP addresses 1.1.1.1 and 1.1.1.2, respectively, the configuration would be, on R1: router bgp 1 neighbor 1.1.1.2 remote-as 2 And on R2: router bgp 2 neighbor 1.1.1.1 remote-as 1

4. Which of the following commands primarily lists counters and status information, instead of configuration settings? a. show snmp b. show snmp community c. show snmp group d. show snmp user

4. A. Of these, only show snmp lists status and counter variables about the operation of the SNMP agent. The other commands list configuration details.

4. Which of the following controllers (if any) from Cisco uses a mostly centralized control plane model? a. Cisco Open SDN Controller b. Cisco Application Policy Infrastructure Controller (APIC) c. Cisco APIC Enterprise Module (APIC-EM) d. None of these controllers uses a mostly centralized control plane.

4. A. The Cisco Open SDN Controller uses an Open SDN model with an OpenFlow Southbound Interface as defined by the Open Networking Foundation (ONF). The ONF SDN model centralizes most control plane functions. The APIC model for data centers partially centralizes control plane functions. The APIC-EM controller (as of time of publication) makes no changes to the control plane of rou

4. An enterprise uses an MPLS Layer 3 VPN with the company headquarters connected plus ten remote sites connected to the service. The enterprise uses EIGRP at all sites, with one router connected to the service from each site. Which of the following are true about the Layer 3 details most likely used with this service and design? (Choose two answers.) a. The WAN uses one IP subnet. b. The WAN uses ten or more IP subnets. c. A remote site router would have one EIGRP neighbor. d. A remote site router would have ten or more EIGRP neighbors.

4. B, C. A Layer 3 MPLS VPN creates an IP service with a different subnet on each access link. With one headquarters router and ten remote sites, 11 access links exist, so 11 subnets are used. As for the EIGRP neighbor relationships, each enterprise router has a neighbor relationship with the MPLS provider edge (PE) router, but not with any of the other enterprise (customer edge) routers. So each remote site router would have only one EIGRP neighbor relationship.

4. Layer 2 switch SW2 connects to several devices: a Layer 2 switch (SW1), a router, a DHCP server, and three PCs (PC1, PC2, and PC3). All PCs are expected to use DHCP to lease their IP addresses. A network engineer implements DHCP snooping on switch SW2. Unknown to the engineer, a malicious attacker is using PC3. Which of the following is the most likely DHCP snooping trust state configuration on SW2 for the ports connected to the listed devices? (Choose two answers.) a. The port connected to the router is untrusted. b. The port connected to switch SW1 is trusted. c. The port connected to PC1 is untrusted. d. The port connected to PC3 is trusted.

4. B, C. Switch ports connected to IT-controlled devices from which DHCP messages may be received should be trusted by the DHCP snooping function. Those devices include IT-controlled DHCP servers and IT-controlled routers and switches. All devices that are expected to be DHCP client devices (like PCs) are then treated as untrusted, because DHCP snooping cannot know beforehand from which ports a DHCP-based attack will be launched. In this case, the ports connected to all three PCs will be treated as untrusted by DHCP snooping.

4. An enterprise has 1000 small retail locations and a central site. The enterprise uses Internet access links to each retail store and DMVPN to securely create a VPN back to the central site. Which of the following answers is true about the operation and configuration of DMVPN? a. The hub router needs at least 1000 tunnel interfaces. b. The hub router needs less than 10 tunnel interfaces. c. All packets between retail stores must route through the central hub site. d. Packets cannot be forwarded from one retail store to another.

4. B. DMVPN uses multipoint GRE tunnels, which means the hub router requires only a single tunnel interface. DMVPN allows designs for which the packets going from one spoke site to another route through the hub site, but it also allows for spoke-to-spoke traffic. In any case, packet forwarding between all the sites is allowed.

4. Which of the following facts determines how often a nonroot bridge or switch sends an 802.1D STP Hello BPDU message? a. The Hello timer as confi gured on that switch. b. The Hello timer as confi gured on the root switch. c. It is always every 2 seconds. d. The switch reacts to BPDUs received from the root switch by sending another BPDU 2 seconds after receiving the root BPDU.

4. B. Nonroot switches forward Hellos received from the root; the root sends these Hellos based on the root's configured Hello timer.

4. An enterprise uses a dual-stack model of deployment for IPv4 and IPv6, using OSPF as the routing protocol for both. Router R1 has IPv4 and IPv6 addresses on its G0/0 and S0/0/0 interfaces only, with OSPFv2 and OSPFv3 enabled on both interfaces for area 0 and the router ID explicitly set for both protocols. Comparing the OSPFv2 and OSPFv3 configuration, which of the following statements is true? a. The OSPFv3 configuration, but not OSPFv2, uses the router-id router-id router subcommand. b. Both protocols use the router-id router-id router subcommand. c. Both protocols use the network network-number wildcard area area-id router subcommand. d. Both protocols use the ipv6 ospf process-id area area-id interface subcommand.

4. B. The OSPFv3 configuration would use ipv6 router ospf process-id, router-id router-id, and then, under each interface, the ipv6 ospf process-id area area-id command. OSPFv2 uses the exact same syntax on the router-id command. Only OSPFv3 uses the ipv6 ospf process-id area area-id interface subcommand, and OSPFv3 does not use the network command.

4. The following text lists output taken from Router R3, which is using HSRP. Subnet 10.1.12.0 uses mask 255.255.255.0. Based on the output of this command, which of the following answers is true? R3# show standby brief Interface Grp Pri P State Active Standby Virtual IP Gi0/0 1 105 Active local 10.1.12.1 10.1.12.2 a. Hosts with a default router setting of 10.1.12.1 are sending their packets to Router R3. b. Hosts with a default router setting of 10.1.12.2 are sending their packets to Router R3. c. Router R3 has an ip address 10.1.12.2 255.255.255.0 command configured on its G0/0 interface. d. Router R3 has an ip address 10.1.12.1 255.255.255.0 command configured on its G0/0 interface.

4. B. The command, taken from R3, lists R3 as HSRP active. That means R3 currently takes on the role of the router with the virtual IP address, listed as 10.1.12.2. R3 will send back Address Resolution Protocol (ARP) Reply messages when hosts send ARP messages looking for 10.1.12.2, and process packets sent to the matching virtual MAC address. The 10.1.12.1 IP address is the interface IP address of the other router in the HSRP group, the one that is standing by to take over for Router R3. Finally, R3 does not configure the virtual IP address with the ip address interface command, but instead with the standby group ip virtual-address interface subcommand.

4. An engineer has successfully configured a Layer 3 switch with SVIs for VLANs 2 and 3. Hosts in the subnets using VLANs 2 and 3 can ping each other with the Layer 3 switch routing the packets. Next week, the network engineer receives a call that those same users can no longer ping each other. If the problem is with the Layer 3 switching function, which of the following could have caused the problem? (Choose two answers.) a. Six (or more) out of ten working VLAN 2 access ports failing due to physical problems b. A shutdown command issued from interface VLAN 4 configuration mode c. VTP on the switch removing VLAN 3 from the switch's VLAN list d. A shutdown command issued from VLAN 2 configuration mode

4. C, D. First, for the correct answers, a Layer 3 switch will not route packets on a VLAN interface unless it is in an up/up state. A VLAN interface will only be up/up if the matching VLAN (with the same VLAN number) exists on the switch. If VTP deletes the VLAN, then the VLAN interface moves to a down/down state, and routing in/out that interface stops. Also, disabling VLAN 2 with the shutdown command in VLAN configuration mode also causes the matching VLAN 2 interface to fail, which makes routing on interface VLAN 2 stop as well. As for the incorrect answers, a Layer 3 switch needs only one access port or trunk port forwarding for a VLAN to enable routing for that VLAN, so nine of the ten access ports in VLAN 2 could fail, leaving one working port, and the switch would keep routing for VLAN 2. A shutdown of VLAN 4 has no effect on routing for VLAN interfaces 2 and 3. Had that answer listed VLANs 2 or 3, it would definitely be a reason to make routing fail for that VLAN interface.

4. Routers R1, R2, and R3 are internal routers in areas 1, 2, and 3, respectively. Router R4 is an ABR connected to the backbone area (0) and to areas 1, 2, and 3. Which of the following answers describes the configuration on Router R4, which is different from the other three routers, that makes it an ABR? a. The abr enable router subcommand. b. The network router subcommands refer to a single nonbackbone area. c. The network router subcommands refer to multiple areas, including the backbone. d. All the ABR's interfaces are assigned to OSPF area 0, while the other routers have their interfaces assigned to a different area, respectively

4. C. An ABR, by definition, connects to the backbone area plus one or more nonbackbone areas. To do so, the configuration enables OSPF so that at least one interface is in area 0 (backbone) and at least one interface is in some other area. For the incorrect answers, the abr enable command is imaginary. Routers internal to a nonbackbone area (which are therefore not ABRs) use OSPF network commands that all refer to the same nonbackbone area. Finally, two routers cannot become OSPF neighbors on a link if their interfaces are in different areas.

4. Two routers using OSPFv2 have become neighbors and exchanged all LSAs. As a result, Router R1 now lists some OSPF-learned routes in its routing table. Which of the following best describes how R1 uses those recently learned LSAs to choose which IP routes to add to its IP routing table? a. Each LSA lists a route to be copied to the routing table. b. Some LSAs list a route that can be copied to the routing table. c. Run some SPF math against the LSAs to calculate the routes. d. R1 does not use the LSAs at all when choosing what routes to add.

4. C. LSAs contain topology information that is useful in calculating routes, but the LSAs do not directly list the route that a router should add to its routing table. In this case, R1 would run a calculation called the Shortest Path First (SPF) algorithm, against the LSAs, to determine what IP routes to add to the IP routing table.

4. Examine the following excerpt from a show command on Router R1: EIGRP-IPv4 Neighbors for AS(1) H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 1 10.1.4.3 Se0/0/1 13 00:05:49 2 100 0 29 0 10.1.5.2 Se0/0/0 12 00:05:49 2 100 0 39 Which of the following answers is true about this router based on this output? a. Address 10.1.4.3 identifi es a working neighbor based on that neighbor's current EIGRP router ID. b. Address 10.1.5.2 identifi es a router that may or may not become an EIGRP neighbor at some point after both routers check all neighbor requirements. c. Address 10.1.5.2 identifi es a working neighbor based on that neighbor's interface IP address on the link between R1 and that neighbor. d. Address 10.1.4.3 identifi es R1's own IP address on interface S0/0/1.

4. C. The output from the show ip eigrp neighbors command lists EIGRP neighbors. The command lists only routers that have passed all EIGRP neighbor checks. The Address column identifies the neighbor based on the neighbor's interface IP address on their common link, not based on the neighbor's EIGRP router ID.

4. Three redundant IPv6 routes exist on R1 to reach IPv6 subnet 9 (2009:9:9:9::/64), a subnet connected to Router R9's G0/0 interface. R1's current successor route uses R2 as the next hop, with feasible successor routes through Routers R3 and R4. Then, another engineer makes changes to the configuration in the network, resulting in R1 having no routes to reach subnet 9. Which of the answers lists one configuration that would result in R1 having no routes at all to subnet 9? a. Make R9's G0/0 interface passive. b. Change R2's EIGRP ASN to some other number, but otherwise keep the same configuration. c. Change the Hello timers on all of R1's interfaces from 5 to 4. d. Change R1's EIGRP ASN to some other number, but otherwise keep the same configuration.

4. D. Before the changes, R1 must have had working neighbor relationships with R2, R3, and R4. Once R1's ASN is changed, R1 cannot be neighbors with those same routers, because the ASNs must be the same number to be neighbors. As for the incorrect answers, changing R2's ASN makes R2's neighborships fail, but R1 should use the redundant routes through R3 and R4. The other two answers cause no failures to routes or neighbors at all.

4. An engineer configures a switch to put interfaces G0/1 and G0/2 into the same Layer 2 EtherChannel. Which of the following terms is used in the configuration commands? a. EtherChannel b. PortChannel c. Ethernet-Channel d. Channel-group

4. D. IOS uses the channel-group configuration command to create an EtherChannel. Then, the term etherchannel is used in the show etherchannel command, which displays the status of the channel. The output of this show command then names the channel a PortChannel. The only answer that is not used somewhere in IOS to describe this multilink channel is Ethernet-Channel.

4. Which of the following behaviors is applied to a low latency queue in a Cisco router or switch? a. Congestion management b. Shaping c. Policing d. Priority scheduling e. Round robin scheduling

4. D. Low Latency Queuing (LLQ) applies priority queue scheduling, always taking the next packet from the LLQ if a packet is in that queue. To prevent queue starvation of the other queues, IOS also applies policing to the LLQ. Most traffic chosen for LLQ classification requires low delay, jitter, and loss, so using a congestion management tool makes little sense. Likewise, applying shaping to an LLQ slows the traffic, and makes no sense with the presence of a policing function already.

4. Which of the following wildcard masks is most useful for matching all IP packets in subnet 10.1.128.0, mask 255.255.240.0? a. 0.0.0.0 b. 0.0.0.31 c. 0.0.0.240 d. 0.0.0.255 e. 0.0.15.255 f. 0.0.248.255

4. E. 0.0.15.255 matches all packets with the same first 20 bits. This is useful when you want to match a subnet in which the subnet part comprises the first 20 bits, as in this case.

4. Which of the following packet header fields can be filtered using IPv6 extended access control lists? a. TCP source and destination port number b. ICMPv6 type and code values c. IPv6 extension header numbers d. IPv6 flow label values e. All of the other answers are correct.

4. E. IPv6 ACLs can filter on any field in the IPv6 header (including flow label, nextheader, etc.). IPv6 ACLs can filter ICMPv6 packets and IPv6 ACLs can filter on the TCP or UDP packets with various source or destination port numbers.

5. A switch has just arrived from Cisco. The switch has never been configured with any VLANs, but VTP has been disabled. An engineer gets into configuration mode and issues the vlan 22 command, followed by the name Hannahs-VLAN command. Which of the following are true? (Choose two answers.) a. VLAN 22 is listed in the output of the show vlan brief command. b. VLAN 22 is listed in the output of the show running-config command. c. VLAN 22 is not created by this process. d. VLAN 22 does not exist in that switch until at least one interface is assigned to that VLAN.

5. A and B. The configured VTP setting of VTP transparent mode means that the switch can configure VLANs, so the VLAN is configured. In addition, the VLAN configuration details, including the VLAN name, show up as part of the running-config file.

5. A LAN design uses a Layer 3 EtherChannel between two switches SW1 and SW2, with Port-Channel interface 1 used on both switches. SW1 uses ports G0/1, G0/2, and G0/3 in the channel. Which of the following are true about SW1's configuration to make the channel be able to route IPv4 packets correctly? (Choose two answers.) a. The ip address command must be on the port-channel 1 interface. b. The ip address command must be on interface G0/1 (lowest numbered port). c. The port-channel 1 interface must be configured with the no switchport command. d. Interface G0/1 must be configured with the routedport command.

5. A, C. With a Layer 3 EtherChannel, the physical ports and the port-channel interface must disable the behavior of acting like a switch port, and therefore act like a routed port, through the configuration of the no switchport interface subcommand. (The routedport command is not an IOS command.) Once created, the physical interfaces should not have an IP address configured. The port-channel interface (the interface representing the EtherChannel) should be configured with the IP address.

5. R1 and R2 are routers that connect to the same VLAN. Which of the answers list an item that can prevent the two routers from becoming OSPFv3 neighbors? (Choose three answers.) a. Mismatched Hello timers b. Mismatched process IDs c. IPv6 addresses in different subnets d. Equal router IDs e. One passive router interface (used on this link)

5. A, D, E. OSPFv3 uses the same rules as OSPFv2 in regard to all these items except the addresses; OSPFv3 does not require that the neighbors have IPv6 addresses in the same subnet. Mismatched Hello timers prevents neighbor relationships, as do duplicate router IDs. Also, neither can have its interface set to passive; otherwise, the neighbor relationship fails to complete. The PIDs can be different or the same because they are not checked as part of the choice to become neighbors.

5. Think about a policing function that is currently working, and also think about a shaping function that is also currently working. That is, the current bit rate of traffic exceeds the respective policing and shaping rates. Which statements are true about these features? (Choose two answers.) a. The policer may or may not be discarding packets. b. The policer is definitely discarding packets. c. The shaper may or may not be queuing packets to slow down the sending rate. d. The shaper is definitely queuing packets to slow down the sending rate.

5. A, D. Policers monitor the bit rate and take action if the bit rate exceeds the policing rate. However, the action can be to discard some packets, or to re-mark some packets, or even to do nothing to the packets, simply measuring the rate for later reporting. For shaping, when a shaper is enabled because the traffic has exceeded the shaping rate, the shaper always queues packets and slows the traffic. There is no option to remark the packets or to bypass the shaping function.

5. ACL 1 has three statements, in the following order, with address and wildcard mask values as follows: 1.0.0.0 0.255.255.255, 1.1.0.0 0.0.255.255, and 1.1.1.0 0.0.0.255. If a router tried to match a packet sourced from IP address 1.1.1.1 using this ACL, which ACL statement does a router consider the packet to have matched? a. First b. Second c. Third d. Implied deny at the end of the ACL

5. A. The router always searches the ACL statements in order, and stops trying to match ACL statements after a statement is matched. In other words, it uses first-match logic. A packet with source IP address 1.1.1.1 would match any of the three explicitly configured commands described in the question. As a result, the first statement will be used.

5. An engineer is considering configuring an ACL on Router R1. The engineer could use ACL A, which would be enabled with the ip access-group A out command on interface G0/1, or ACL B, which would be enabled with the ip access-group B in command on that same interface. R1's G0/1 interface uses IPv4 address 1.1.1.1. Which of the answers are true when comparing these options? (Choose two answers.) a. ACL A creates more risk of filtering important overhead traffic than ACL B. b. ACL B creates more risk of filtering important overhead traffic than ACL A. c. A ping 1.1.1.1 command on R1 would bypass ACL A even if enabled. d. A ping 1.1.1.1 command on R1 would bypass ACL B even if enabled.

5. B and C. A router bypasses the ACL logic for its own outbound ACLs for packets created by that router. Routers do not make any kind of exception for inbound packets. As a result, ACL B creates more risk than ACL A, because B is enabled as an inbound ACL. The ping 1.1.1.1 command in two answers is a self-ping of a router's Ethernet interface. As a result, the router would bypass any outbound ACL logic on that interface, but consider any inbound ACL logic. So router R1 would bypass the logic of ACL A, which would be enabled as an outbound ACL on R1's G0/1 interface.

5. Two neighboring LAN switches are connected with an operational 802.1Q trunk. Switch SW1 has been configured with the vtp mode client, vtp domain fred, and vtp version 2 commands. SW1 has no other VTP configuration commands configured. Which answer lists a possible reason why switch SW2, on the other end of the trunk, is not synchronizing its VLAN database with switch SW1? (Choose two answers.) a. SW2 has a vtp version 1 command confi gured. b. SW2 has a vtp password G0BeeZ command confi gured. c. SW2 has a vtp domain Fred command confi gured. d. SW2 has a vtp mode client command confi gured.

5. B, C. The VTP domain name must match on two neighboring VTP switches, or they ignore each other's messages. The domain name is case sensitive, making the answer with domain name "Fred" be correct. Additionally, switch SW1 does not have a vtp password command configured per the question stem. If SW2 were to be configured per the other correct answer, then SW1 would not have a VTP password, SW2 would, and the two switches would ignore each other's VTP messages. (If configured on one switch, both must have the same case-sensitive password configured.) As for the incorrect answers, the VTP version does not have to match on neighboring switches for them to be able to synchronize. Additionally, two neighboring VTP client mode switches will synchronize, which is what the question asked. Neither could be used to configure new VLANs, but both would synchronize with the other.

5. Which of the following RSTP port states have the same name and purpose as a port state in traditional 802.1D STP? (Choose two answers.) a. Blocking b. Forwarding c. Listening d. Learning e. Discarding

5. B, D. RSTP uses port states forwarding, learning, and discarding. Forwarding and learning perform the same functions as the port states used by traditional 802.1D STP.

5. Consider the following excerpt from the output of a show command: Serial0/0/1 is up, line protocol is up Hardware is GT96K Serial Internet address is 192.168.2.1/24 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation PPP, LCP Open Open: CDPCP, IPCP, loopback not set Which of the following are true about this router's S0/0/1 interface? (Choose two answers.) a. The interface is using HDLC. b. The interface is using PPP. c. The interface currently cannot pass IPv4 traffic. d. The link should be able to pass PPP frames at the present time.

5. B, D. The output lists encapsulation PPP, meaning that it is configured to use PPP. The line and protocol status are both up, LCP is open, and both CDPCP and IPCP are open, meaning that IP and CDP packets can be sent over the link.

5. R1 and R2 are routers that connect to the same VLAN. Which of the answers list an item that can prevent the two routers from becoming EIGRP for IPv6 neighbors? (Choose two answers.) a. Mismatched Hello timers b. Mismatched ASNs c. IPv6 addresses in different subnets d. Using the same router ID e. One passive router interface (used on this link)

5. B, E. EIGRP for IPv6 uses the same rules as EIGRP for IPv4 in regard to all these items except the addresses; EIGRP for IPv6 does not require that the neighbors have IPv6 addresses in the same subnet. The two routers must use the same ASN, and neither can have its interface set to passive; otherwise, the neighbor relationship fails to complete. However, the Hello timer can be different, the router IDs can be the same, and the IPv6 addresses can be in different subnets.

5. The implicit rules at the bottom of IPv6 ACLs are there to permit which of the following packets? a. Router Solicitation (RS) and Router Advertisement (RA) messages b. Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages c. All ICMPv6 messages on a LAN interface d. All IPv6 multicast packets on a LAN interface

5. B. Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages are essential to the function of Neighbor Discovery Protocol (NDP) and establishment and maintenance of the IPv6 interface neighbor cache. If these packets were to be blocked, the neighbor cache entries on that interface would time out and affect reachability to the next-hop device.

5. Which of the following OSPF neighbor states is expected when the exchange of topology information is complete between two OSPF neighbors? a. 2-way b. Full c. Up/up d. Final

5. B. Neighboring OSPF routers that complete the database exchange are considered fully adjacent and rest in a full neighbor state. The up/up and final states are not OSPF states at all. The 2-way state is either an interim state or a stable state between some routers on the same VLAN.

5. Which of the following is true about the concept of EIGRP feasible distance? a. A route's feasible distance is the calculated metric of a feasible successor route. b. A route's feasible distance is the calculated metric of the successor route. c. The feasible distance is the metric of a route from a neighboring router's perspective. d. The feasible distance is the EIGRP metric associated with each possible route to reach a subnet.

5. B. The feasible distance (FD) is, for all known routes to reach a subnet, the metric for the best of those routes. The best route is called the successor route, and it is added to the IP routing table.

5. A network engineer takes four 2960-X switches and creates a switch stack using either FlexStack or FlexStack-Plus stacking from Cisco. Now consider data plane functions, such as frame forwarding; control plane functions, such as STP and VTP; and management plane functions, such as Telnet and SSH support. Once the stack is cabled and working, which of the following is true about how the stack of four switches works? a. The stack acts as one switch for data plane functions, and separate switches for control and management plane functions. b. The stack acts as one switch for data plane and control plane functions, and separate switches for management plane functions. c. The stack acts as one switch for data plane, control plane, and management plane functions. d. The stack does not act as one switch for data, control, or management plane functions, instead providing backup uplinks if all of one switch's uplinks fail.

5. C. A switch stack connects the switches with stacking modules and stacking cables so that they can communicate directly. Functionally, the switches in the stack act as a single logical switch. For instance, to manage the switches in the stack, an engineer would log in to one switch, with one IP address, and see one configuration file for the whole switch stack; STP and VTP would run for the logical switch as a whole; and frame forwarding would occur on one switch, forwarding on all ports in the stack.

5. Which of the following best describes a virtual network function in a public cloud service? a. A subset of a physical networking device, configured by the cloud provider and allocated for use by that customer only b. A networking function implemented by the cloud provider for the customer, but with no direct customer access to the server that provides the service c. A networking function implemented by the cloud provider for the customer as a VM that is directly accessible and configurable by the customer d. Any networking feature implemented on a VM in a cloud service

5. C. A virtual network function (VNF) is a virtual version of a networking appliance, such as a virtual router (like the Cisco CSR) or virtual firewall (like the Cisco ASAv). VNFs are deployed as a VM, with customer access to the user interface, so that customers can then configure the VNF to meet their needs. Cloud providers can implement many networking services that create the cloud network, but not give the customer direct access to the VM or appliance. For instance, public cloud providers typically provide DNS services and address assignment services that use DHCP behind the scenes, but without giving the customer direct access to a VM that implements a DNS or DHCP server.

5. Which of the following statements is true about ICMP Echo-based IP SLA? a. It sends messages to mimic Voice over IP (VoIP) traffic to measure jitter. b. It requires the use of one router as the source and another as the responder. c. It can collect and aggregate historical statistics. d. It sends ICMP Echo messages to measure jitter.

5. C. IP Service Level Agreement (IP SLA) can generate a variety of different types of probes, including some that use ICMP Echo messages, and some that mimic voice traffic. However, the question asks about "ICMP Echo-based" IP SLA, referring to the specific IP SLA probe that sends ICMP Echo Request messages. ICMP Echo probes with IP SLA do not require a router to be configured as an IP SLA responder, although many other types of IP SLA probes do require a responder. The Echo probes send a normal ICMP Echo Request, so the probe can be sent to any IP address, relying on that host to send back a normal ICMP Echo Reply. IP SLA on the source router will gather basic statistics. With the ICMP Echo probe, the probe does not measure jitter (ruling out another incorrect answer), but it does measure round-trip time (RTT). These statistics can be

5. Two routers, R1 and R2, are configured to be part of an HSRP group. R1's configuration includes the standby 1 priority 1 command, and R2's configuration includes the standby 1 priority 2 command. R1 powers up. An hour later, R2 powers up. Which of the following answers is true about which router is now the HSRP active router? a. R2 is active regardless of other configuration settings. b. R1 is active regardless of other configuration settings. c. R2 is active only if R2 is also configured with standby 1 preempt. d. R1 is active only if R1 is also configured with no standby 1 preempt.

5. C. R2 has a better priority because the priority value is higher. However, because R1 comes up first, R1 becomes HSRP active before R2 boots. R2 must then have preemption configured, otherwise it will not preempt R1 to become active. As for the wrong answers, R1's preemption setting does not matter in this case. The other two wrong answers state that a router is active regardless of other settings, and the answer is dependent on other configuration.

5. Examine the following excerpt from a router's CLI: P 10.1.1.0/24, 1 successors, FD is 2172416 via 10.1.6.3 (2172416/28160), Serial0/1 via 10.1.4.2 (2684416/2284156), Serial0/0 via 10.1.5.4 (2684416/2165432), Serial1/0 Which of the following identifies a next-hop IP address on a feasible successor route? a. 10.1.6.3 b. 10.1.4.2 c. 10.1.5.4 d. It cannot be determined from this command output.

5. C. The first number in parentheses is the computed metric for a route, and the second number is the reported distance (RD) for the route. The route through 10.1.6.3 is the successor route, because the first number in parentheses on this line matches the feasible distance (FD) on the first line. For the other two routes, only the third route's RD is less than the feasible distance (the metric of the successor route), making this route, with next-hop address 10.1.5.4, a feasible successor route.

5. An enterprise uses Cisco IOS routers and DSL connections to local ISPs for their retail locations. The ISPs require the use of PPPoE. The routers at each retail site use dynamically learned public IP addresses as learned from the ISPs. Each router uses its F0/0 interface to connect to an external DSL modem, which then connects to a phone line. Which of the following is the most likely choice for configuring the router to use the IP address as assigned by the ISP? a. Interface F0/0 has an ip address dhcp interface subcommand. b. Some dialer interface has an ip address dhcp interface subcommand. c. Some dialer interface has an ip address negotiated interface subcommand. d. Interface F0/0 has an ip address negotiated interface subcommand.

5. C. With PPPoE, the physical interface disables Layer 3 processing with the no ip address command. A dialer interface is used as the Layer 3 interface. For address assignment, the ISP typically uses PPP's IP Control Protocol (IPCP) to assign the address to the customer router; to enable that function on the customer router, use the ip address negotiated command. Note that the ip address dhcp command is a valid command if using DHCP to assign the IP address to the router.

5. Host A and Host B sit in two different subnets. The path between the subnets of these two hosts runs through three different Layer 3 forwarding devices (routers and Layer 3 switches). A network engineer uses the APIC-EM Path Trace ACL Analysis tool to analyze the path used for Host A to send packets to Host B. Which part of the function is done specifically by the ACL Analysis or ACL Trace part of the tool? a. Discovery of the topology that exists between the two hosts b. Analysis of the Layer 3 forwarding decisions in the path from Host A to B c. Analysis of the Layer 2 forwarding decisions in the path from Host A to B d. Analysis of the impact of ACLs on the packets that would flow from Host A to B

5. D. APIC-EM does all the features described in the answers. APIC-EM has a built-in function to discover the topology of a network, using a variety of protocols such as SSH, CDP, and LLDP. Once discovered, the APIC-EM Path Trace feature analyzes the forwarding tables on each device in comparison to a source and destination as typed in by an APIC-EM user. Path Trace then determines the path through the network, including the Layer 2 and Layer 3 paths. The feature that uses the name Path Trace ACL Analysis (or Path Trace ACL Trace, or a similar name) refers to the additional analysis done by APIC-EM to then compare that imaginary packet to the ACLs that exist in the network. The tool shows the ACLs and points out which ACLs would deny (that is, discard) the packet based on its current configuration.

5. Which of the following answers is most accurate about access link options for an MPLS network? a. Uses only TDM (T1, T3, E1, E3, etc.) b. Uses only Ethernet c. Uses only DSL and cable d. Uses a wide variety of Layer 1 and Layer 2 networking technologies

5. D. Architecturally, MPLS allows for a wide variety of access technologies. Those include TDM (that is, serial links), Frame Relay, ATM, Metro Ethernet, and traditional Internet access technologies such as DSL and cable.

5. An engineer connects to Router R1 and issues a show ip ospf neighbor command. The status of neighbor 2.2.2.2 lists FULL/BDR. What does the BDR mean? a. R1 is an Area Border Router. b. R1 is a backup designated router. c. Router 2.2.2.2 is an Area Border Router. d. Router 2.2.2.2 is a backup designated router.

5. D. The BDR designation on this line is for backup designated router (BDR). On this command, this notation means that the neighbor (2.2.2.2) is the BDR, not the local router on which the command was issued (R1 in this case).

5. Examine the following first seven lines of output from the show spanning-tree command on a Cisco switch: SW1# show spanning-tree vlan 5 VLAN0005 Spanning tree enabled protocol rstp Root ID Priority 32773 Address 1833.9d7b.0e80 Cost 15 Port 25 (GigabitEthernet0/1) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Which of the following answers is true about the switch on which this command output was gathered? a. The root switch's MAC address is 1833.9d7b.0e80 and the local switch is the root. b. The local switch's MAC address is 1833.9d7b.0e80 and it is not the root. c. This switch uses STP and not RSTP. d. This switch uses RSTP.

5. D. The first set of messages list the root's MAC address (1833.9d7b.0e80). These lines also list the cost to reach the root (15) rather than the phrase 'this bridge is the root'. Those facts combine to rule out two answers. Second, the "protocol rstp" near the top of the output positively identifies that the switch is using RSTP, as configured with the spanning-tree mode rapid-pvst global configuration command

5. An enterprise router (R1) has a working eBGP peer relationship with ISP router R2. Both routers use the default setting of no auto-summary. Examine the following output from R1. Based on that output, which of the following answers, when added to R1's BGP configuration, causes R1 to advertise a BGP route to Router R2? R1# show ip route 200.1.1.0 255.255.255.0 longer-prefixes 200.1.1.0/24 is variably subnetted, 3 subnets, 3 masks C 200.1.1.0/27 is directly connected, Loopback1 L 200.1.1.1/32 is directly connected, Loopback1 O 200.1.1.32/28 [110/2] via 10.1.1.1, 03:11:00, GigabitEthernet0/2 a. network 200.1.1.0 mask 255.255.255.0 b. network 200.1.1.0 c. network 200.1.1.0 mask 255.255.255.240 d. None of the other answers causes R1 to advertise a route to R2.

5. D. To cause the injection of a route from the IP routing table to the BGP table, the network command must match a route in the IP routing table, unless the auto-summary command has also been added to the configuration. One answer lists prefix 200.1.1.0, but mask 255.255.255.0, and both must match the IP route—and the mask does not match. Likewise, the command with subnet 200.1.1.0 and mask 255.255.255.240 does not match any of the routes, either. The network 200.1.1.0 command implies the default mask—a Class C default mask of 255.255.255.0 in this case—and again does not match any of the routes in the routing table. Note that the commands that would match routes in this router's routing table include network 200.1.1.0 mask 255.255.255.224, which matches connected subnet 200.1.1.0/27, and network 200.1.1.32 mask 255.255.255.240, which matches the one OSPF-learned route.

6. Switches SW1 and SW2 connect through an operational trunk. The engineer wants to use VTP to communicate VLAN configuration changes. The engineer configures a new VLAN on SW1, VLAN 44, but SW2 does not learn about the new VLAN. Which of the following configuration settings on SW1 and SW2 would be a potential root cause why SW2 does not learn about VLAN 44? (Choose two answers.) a. VTP domain names of larry and LARRY, respectively b. VTP passwords of bob and BOB, respectively c. VTP pruning enabled and disabled, respectively d. VTP modes of server and client, respectively

6. A, B. The case-sensitive domain names must be equal, and the case-sensitive passwords must be equal. The switches must also connect using a trunk before VTP will work. It is normal to have some switches as servers and some as clients. A mismatched pruning configuration setting does not prevent the synchronization of VLAN databases.

6. Examine the output taken from a router using IP SLA. Which of the following answers list a fact that can be confirmed based on this output? (Choose two answers.) R3# show ip sla summary IPSLAs Latest Operation Summary Codes: * active, ^ inactive, ~ pending ID Type Destination Stats Return Last (ms) Code Run ----------------------------------------------------------------------- *1 icmp-echo 10.1.1.1 RTT=384 OK 54 seconds ago a. The probe sends ICMP Echos to address 10.1.1.1. b. The output confirms that an Echo Reply was received back as well. c. The one-way delay through the network for the latest test was 384 ms. d. The "1" means that this output is the first historical record for this probe.

6. A, B. The show ip sla summary command lists one line of information about the most recent attempt to perform the actions of an IP SLA probe. The Type implies an ICMP Echo probe, and the destination defines the IP address to which the Echo is sent, accounting for one correct answer. The "OK" return code means not only was the probe message sent, but in this case, that an ICMP Echo Reply packet was received back. For the two incorrect answers, the Stats column lists the round-trip time (RTT), not the one-way delay as mentioned in one answer. Also, the "1" on the far left of the output refers to the IP SLA operation number.

6. Another engineer has configured HSRP on two routers that connect to the same LAN. You connect to the console of one of the routers, and see this log message: *Mar 12 17:18:19.123: %IP-4-DUPADDR: Duplicate address 10.2.2.2 on GigabitEthernet0/0, sourced by 0000.0c9f.f002 Which of the answers list an HSRP configuration mistake that would cause the router to list this message? (Choose two answers.) a. The two HSRP routers are configured with different HSRP group numbers. b. The local router is filtering all incoming HSRP messages. c. The two HSRP routers are configured with different HSRP version numbers. d. The two HSRP routers have configured different virtual IP addresses.

6. A, C. Two HSRP misconfigurations cause both HSRP routers to attempt to use the same virtual IP address (VIP), at the same time, because both routers believe that they should be active. With a correct configuration other than mismatched group numbers, the two routers act independently, both using the VIP, resulting in the duplicate address message. The same kind of logic applies when the two routers have correct configuration other than a mismatched HSRP version: they do not act together, but act independently, both use the address, and then detect the duplicate use of the address. As for the incorrect answers, an ACL that prevents a router from even receiving the HSRP messages will prevent that router from noticing the duplicate use of the VIP, so it does not list the duplicate address log message. Finally, if the configuration mistake is that the two routers configure two different VIPs, then they are using different addresses, so there is no need to issue a message about using duplicate addresses.

6. RSTP adds some concepts to STP that enable ports to be used for a role if another port on the same switch fails. Which of the following statements correctly describe a port role that is waiting to take over for another port role? (Choose two answers.) a. An alternate port waits to become a root port. b. A backup port waits to become a root port. c. An alternate port waits to become a designated port. d. A backup port waits to become a designated port.

6. A, D. With RSTP, an alternate port is an alternate to the root port when a switch's root port fails. A backup port takes over for a designated port if the designated port fails.

6. Two routers, R1 and R2, connect to each other using three serial links. The network engineer configures these links to be part of the same multilink PPP group, along with configuring CHAP configuration, IPv4, and OSPFv2 using interface configuration. Which of the following answers list a configuration command along with the correct configuration mode for that command? (Choose two answers.) a. encapsulation ppp while in multilink interface configuration mode b. ip address address mask while in serial interface configuration mode c. ppp authentication chap while in multilink interface configuration mode d. ip ospf 1 area 0 while in serial interface configuration mode e. ppp multilink while in serial interface configuration mode

6. A, E. Both the multilink interface and each of the serial interfaces need the encapsulation ppp and ppp multilink commands, which account for both of the correct answers to this question. Two of the three incorrect answers list a command related to a Layer 3 feature (ip address and ip ospf), which are useful, but would be used in multilink interface mode instead of serial interface configuration mode. The other incorrect answer lists ppp authentication chap, which would not be used on the Layer 3 multilink interface, but instead on the serial interfaces.

6. Router R1's EIGRP process knows of three possible routes to subnet 1. One route is a successor, and one is a feasible successor. R1 is not using the variance command to allow for unequal-cost load balancing. Which of the following commands shows information about the feasible successor route, including its metric, whether as EIGRP topology information or as an IPv4 route? a. show ip eigrp topology b. show ip eigrp database c. show ip route eigrp d. show ip eigrp interfaces

6. A. By definition, the successor route is the best route to reach a subnet, and is the one route EIGRP always puts in the IP routing table. So, the show ip route eigrp command lists this route, including the metric. The show ip eigrp topology command lists both successor and feasible successor routes, including their metrics. The show ip eigrp interfaces command does not list route information, and the show ip eigrp database command is not a valid IOS command.

6. An enterprise connects 20 sites into an MPLS VPN WAN. The enterprise uses OSPF for IPv4 routes at all sites. Consider the OSPF area design options, and the PE-CE links. Which of the following answers is most accurate about OSPF areas and the PE-CE links? a. The PE-CE link may or may not be chosen to be in backbone area 0. b. The PE-CE link must not be in the backbone area 0. c. The PE-CE link must be in the backbone area 0. d. The PE-CE link will not be in any OSPF area.

6. A. The PE-CE link is the link between the customer edge (CE) router and the MPLS provider's provider edge (PE) router. When using OSPF, that link will be configured to be in some area. OSPF design allows for that link to be in the backbone area, or not, through the use of the OSPF super backbone, which exists between all the PE routers.

6. The output of the show ipv6 eigrp neighbors command from R2 lists one neighbor. Which of the following answers is correct about the meaning of the output of the command in this example? R2# show ipv6 eigrp neighbors EIGRP-IPv6 Neighbors for AS(1) H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 0 Link-local address: Gi0/0 11 06:46:11 1 100 0 30 FE80::FF:FE22.2222 a. The neighbor's link-local address on its common link must be FE80::FF:FE22:2222. b. The neighbor's EIGRP for IPv6 router ID must be FE80::FF:FE22:2222. c. R2's link-local address on its common link must be FE80::FF:FE22:2222. d. R2's EIGRP for IPv6 router ID must be FE80::FF:FE22:2222.

6. A. The output of this command identifies the neighbor router, based on the neighbor's link-local address on the link between the two routers. The two incorrect answers that mention the router ID have to be incorrect because EIGRP for IPv6 router IDs are 32-bit values represented as dotted-decimal numbers, so they look like IPv4 addresses.

6. Which of the following commands identify switch interfaces as being trunking interfaces: interfaces that currently operate as VLAN trunks? (Choose two answers.) a. show interfaces b. show interfaces switchport c. show interfaces trunk d. show trunks

6. B and C. The show interfaces switchport command lists both the administrative and operational status of each port. When a switch considers a port to be trunking, this command lists an operational trunking state of "trunk." The show interfaces trunk command lists a set of interfaces: the interfaces that are currently operating as trunks. So, both these commands identify interfaces that are operational trunks.

6. A LAN design uses a Layer 3 EtherChannel between two switches SW1 and SW2, with port-channel interface 1 used on both switches. SW1 uses ports G0/1 and G0/2 in the channel. However, only interface G0/1 is bundled into the channel and working. Think about the configuration settings on port G0/2 that could have existed before adding G0/2 to the EtherChannel. Which answers identify a setting that could prevent IOS from adding G0/2 to the Layer 3 EtherChannel? (Choose two answers.) a. A different STP cost (spanning-tree cost value) b. A different speed (speed value) c. A default setting for switchport (switchport) d. A different access VLAN (switchport access vlan vlan-id)

6. B, C. With a Layer 3 EtherChannel, two configuration settings must be the same on all the physical ports, specifically the speed and duplex as set with the speed and duplex commands. Additionally, the physical ports and port-channel port must all have the no switchport command configured to make each act as a routed port. So, having a different speed setting, or being configured with switchport rather than no switchport, would prevent IOS from adding interface G0/2 to the Layer 3 EtherChannel. As for the wrong answers, both have to do with Layer 2 configuration settings. Once Layer 2 operations have been disabled because of the no switchport command, those settings related to Layer 2 that could cause problems on Layer 2 EtherChannels do not then cause problems for the Layer 3 EtherChannel. So, Layer 2 settings about access VLANs, trunking allowed lists, and STP settings, which must match before an interface can be added to a Layer 2 EtherChannel, do not matter for a Layer 3 EtherChannel.

6. The example shows an excerpt from the show ipv6 route ospf command on a router (R1). Which of the answers are correct about the interpretation of the meaning of the output of this command? (Choose two answers.) R1# show ipv6 route ospf OI 2001:DB8:1:4::/64 [110/129] via FE80::FF:FE00:1, Serial0/0/1 a. 110 is the metric for the route. b. S0/0/1 is an interface on R1. c. FE80::FF:FE00:1 is a link-local address on R1. d. OI means that the route is an interarea OSPF route.

6. B, D. The second line lists the forwarding instructions for the route, specifically the link-local address of the neighboring router and the local router's outgoing interface. These facts identify one correct and one incorrect answer. The OI code indeed means OSPF and interarea; intra-area routes simply omit the I. In brackets, the first number is the administrative distance, and the second number (129 in this case) is the metric.

6. An enterprise uses Cisco IOS routers and DSL connections to local ISPs for their retail locations. The ISPs require the use of PPPoE. The following output listed comes from one such router (R1). Which of the following answers are true about the configuration on Router R1 and its current PPPoE state? (Choose two answers.) R1# show pppoe session 1 client session Uniq ID PPPoE RemMAC Port VT VA State SID LocMAC VA-st Type N/A 1 0200.0000.3333 Gi0/0 Di1 Vi1 UP 0200.0000.3003 UP a. The configuration includes PPPoE commands under interface virtual-access 1. b. Dialer interface 1 and virtual-access 1 are bound together. c. Interface G0/0 is using MAC address 0200.0000.3333. d. The PPPoE session is currently working.

6. B, D. The show pppoe session command lists many key facts about a current PPPoE session. As for the correct answers, the State of UP on the far right confirms that the PPPoE session is working correctly. Also, the listing of the Di1 (Dialer1) and Vi1 (Virtual-access 1) interfaces implies that the two interfaces are bound by the PPPoE session. As for the incorrect answers, MAC 0200.0000.3333 is in use, but by the ISP router. The heading lines list RemMAC (Remote MAC) above and LocMAC (Local MAC) below, so it is the lower of the two MAC addresses (0200.0000.3003) that is used by the local router, R1. Also, the PPPoE configuration is added to the dialer interface and the physical interface (G0/0 in this case), but the virtual-access interface is not directly configured. Instead, IOS generates its configuration from the configuration listed under the dialer interface.

6. The following output shows the last lines of output of a show spanning-tree command extracted from a Cisco switch running IOS: SW1# show spanning-tree vlan 10 ! lines omitted Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- ----------------------- Fa0/1 Desg FWD 100 128.1 P2p Edge Fa0/2 Desg FWD 19 128.2 Shr Gi0/1 Desg FWD 4 128.25 P2p Gi0/2 Root FWD 4 128.26 P2p The answers all mention an interface and the state listed in the Type column of the output, along with a reason why that port should be listed as that type of STP port. Which answers list what could be a correct reason for the interface to be listed as that type of STP port? (Choose two answers.) a. Fa0/1 is P2p Edge because of the spanning-tree rstp edge interface subcommand. b. Fa0/2 is Shr because Fa0/2 uses half duplex. c. Gi0/1 is P2p because it is a VLAN trunk. d. Gi0/2 is P2p because the switch had no reason to make it Shr or P2p Edge.

6. B, D. This question requires that you work through the reasons why a port is listed as a particular type of STP port per the Type column in the output of the show spanning-tree vlan 10 command. To begin, keep in mind that a port must have PortFast enabled to be listed as an edge port. That configuration requires either the spanning-tree portfast interface subcommand or through setting the switch to use PortFast as a default with the spanning-tree portfast default global command. Answer choice A shows a type that includes "edge" and the reason listed has nothing to do with PortFast, so that answer is incorrect. For the other incorrect answer, C, the trunking status of a port does not impact the STP Type as listed in the output. Answer B is correct because any port that is using half duplex, either through negotiation or by configuration, is considered to be a shared port, as noted with "Shr" in the type column. Answer D is correct because if a switch has no reason to make a port act as a shared port, or as an edge port, the switch treats it as a point-to-point port.

6. Which of the following access-list commands matches all packets sent from hosts in subnet 172.16.4.0/23? a. access-list 1 permit 172.16.0.5 0.0.255.0 b. access-list 1 permit 172.16.4.0 0.0.1.255 c. access-list 1 permit 172.16.5.0 d. access-list 1 permit 172.16.5.0 0.0.0.127 Foundation Topics

6. B. One wrong answer, with wildcard mask 0.0.255.0, matches all packets that begin with 172.16, with a 5 in the last octet. One wrong answer matches only specific IP address 172.16.5.0. One wrong answer uses a wildcard mask of 0.0.0.128, which has only one wildcard bit (in binary), and happens to only match addresses 172.16.5.0 and 172.16.5.128. The correct answer matches the range of addresses 172.16.4.0- 172.16.5.255.

6. An engineer migrates from a more traditional OSPFv2 configuration that uses network commands in OSPF configuration mode to instead use OSPFv2 interface configuration. Which of the following commands configures the area number assigned to an interface in this new configuration? a. The area command in interface configuration mode b. The ip ospf command in interface configuration mode c. The router ospf command in interface configuration mode d. The network command in interface configuration mode

6. B. With OSPFv2 interface configuration mode, the configuration looks just like the traditional configuration, with a couple of exceptions. The network router subcommand is no longer required. Instead, each interface on which OSPF should be enabled is configured with an ip ospf process-id area area-id interface subcommand. This command refers to the OSPF routing process that should be enabled on the interface, and specifies the OSPFv2 area.

6. An engineer configures an ACL but forgets to save the configuration. At that point, which of the following commands display the configuration of an IPv4 ACL, including line numbers? (Choose two answers.) a. show running-config b. show startup-config c. show ip access-lists d. show access-lists

6. C and D. The show ip access-lists and show access-lists commands both display the configuration of IPv4 access lists, including ACL line numbers. Neither the show running-config nor show startup-config commands list the ACL line numbers; in this case, the startup-config file would not contain the ACL configuration at all.

6. A queuing system has three queues serviced with round robin scheduling and one low latency queue that holds all voice traffic. Round robin queue 1 holds predominantly UDP traffic, while round robin queues 2 and 3 hold predominantly TCP traffic. The packets in each queue happen to have a variety of DSCP markings per the QoS design. In which queues would it make sense to use a congestion avoidance (drop management) tool? (Choose two answers.) a. The LLQ b. Queue 1 c. Queue 2 d. Queue 3

6. C, D. Drop management relies on the behavior of TCP, in that TCP connections slow down sending packets due to the TCP congestion window calculation. Voice traffic uses UDP, and the question states that queue 1 uses UDP. So, queues 2 and 3 are reasonable candidates for using a congestion management tool.

6. Which of the following is true about the concept of EIGRP reported distance? a. A route's reported distance is the calculated metric of a feasible successor route. b. A route's reported distance is the calculated metric of the successor route. c. A route's reported distance is the metric of a route from a neighboring router's perspective. d. The reported distance is the EIGRP metric associated with each possible route to reach a subnet.

6. C. A route's reported distance (RD) is the metric used by the neighbor that advertised the route. A router uses it to determine which routes meet the feasibility condition for whether the route can be a feasible successor route.

6. A company has a small/medium-sized network with 15 routers and 40 subnets and uses OSPFv2. Which of the following is considered an advantage of using a singlearea design as opposed to a multiarea design? a. Reduces the processing overhead on most routers. b. Status changes to one link may not require SPF to run on all other routers. c. Simpler planning and operations. d. Allows for route summarization, reducing the size of IP routing tables.

6. C. The correct answer is the one advantage of using a single-area design. The three wrong answers are advantages of using a multiarea design, with all reasons being much more important with a larger internetwork.

7. An enterprise uses Cisco IOS routers and DSL connections to local ISPs for their retail locations. The ISPs require the use of PPPoE. A network engineer connects to the console of one router at a retail office, issues the show pppoe session command, and the router just returns a command prompt, with no lines of output. If you knew the problem was related to the configuration on the local router, which one of the four following areas would be the best area to recommend for your colleagues to investigate in their next troubleshooting step? a. Look at the commands on the physical Ethernet interface b. Look at the dialer interface commands specific to PPP c. Look at the commands specific to IPv4 address learning d. Look at the commands in the running-config file for the virtual-access interface

7. A. The show pppoe session command lists a short group of messages about each PPPoE session once the router is trying to establish that session. However, a router does not even attempt to start a PPPoE session until PPPoE has been enabled on the physical interface using the pppoe enable command. (Note that the pppoe-client dial-pool-number number interface subcommand on the physical interface causes IOS to automatically add the pppoe enable command as well.) Until these commands are added, the router makes no attempt to create a PPPoE session, and as a result, the show pppoe session command lists no output at all. For the incorrect answers, if the dialer interface's commands related to PPP were incorrect or missing, there might be a problem, but those problems would not result in no output at all from the show pppoe session command. Instead the command would list some status messages. Similarly, any errors in the configuration related to IP address learning would not prevent the show pppoe session command from listing output. Finally, the virtual-access interface does not have any specific configuration; its configuration is generated by the router.

7. Which of the following configuration settings on a router does not influence which IPv4 route a router chooses to add to its IPv4 routing table when using OSPFv2? a. auto-cost reference-bandwidth b. delay c. bandwidth d. ip ospf cost

7. B. SPF calculates the cost of a route as the sum of the OSPF interface costs for all outgoing interfaces in the route. The interface cost can be set directly (ip ospf cost), or IOS uses a default based on the reference bandwidth and the interface bandwidth. Of the listed answers, delay is the only setting that does not influence OSPFv2 metric calculations.

7. Router R1 has four routes to subnet 2. The one successor route has a metric of 100, and the one feasible successor route has a metric of 350. The other routes have metrics of 450 and 550. R1's EIGRP configuration includes the variance 5 command. Choose the answer that refers to the highest-metric route to subnet 2 that will be visible in the output of the show ip route eigrp command on R1. a. The successor route (metric 100) b. The feasible successor route (metric 350) c. The route with metric 450 d. The route with metric 550

7. B. The unequal-cost load-balancing features allow IOS to place multiple unequal-cost routes into the routing table. The restrictions are that the metric must be less than or equal to variance times the feasible distance (5 times 100 in this case), so three of the routes meet this requirement, ruling out the route with metric 550. This feature also allows only successor and feasible successor routes, ruling out the route with metric 450. Of the two routes that meet both requirements, the route with metric 350 has the highest metric, as requested in the question text.

7. Consider the following excerpt from the output of a show interfaces command on an interface configured to use PPP: Serial0/0/1 is up, line protocol is down Hardware is GT96K Serial Internet address is 192.168.2.1/24 A ping of the IP address on the other end of the link fails. Which of the following are reasons for the failure, assuming that the problem listed in the answer is the only problem with the link? (Choose two answers.) a. The CSU/DSU connected to the other router is not powered on. b. The IP address on the router at the other end of the link is not in subnet 192.168.2.0/24. c. CHAP authentication failed. d. The router on the other end of the link has been configured to use HDLC. e. None of the above.

7. C, D. The question states a problem symptom with an interface state of line status up, and protocol status down. One incorrect answer refers to a physical layer problem, which usually results in a line status (first status code) value of down. Another incorrect answer mentions an IP address mismatch on the ends of a link; this mistake allows both the line and protocol status of the interface to reach an up state. The two correct answers result in the router having a line status of up, but a protocol status of down.

7. Router R1 has been configured as a dual-stack IPv4/IPv6 router, using interfaces S0/0/0, S0/0/1, and GigabitEthernet0/1. As a new engineer hired at the company, you do not know whether any of the interfaces are passive. Which of the following commands lets you find whether G0/1 is passive, either by the command listing that fact or by that command leaving passive interfaces out of its list of interfaces? a. show ipv6 ospf interface brief b. show ipv6 protocols c. show ipv6 ospf interface G0/1 d. show ipv6 ospf interface passive

7. C. The correct answer lists detailed information about OSPFv3 related to interface G0/1, including a notation that the interface is passive (if it is). Of the incorrect answers, in the show ipv6 ospf interface passive command, the passive keyword does not exist. The other two commands list all OSPFv3-enabled interfaces on the router, but the list includes passive interfaces, with no notation about which are passive and which are not.

7. Host1 and Host2 connect to ports F0/1 and F0/2 on a LAN switch, respectively, so that frames sent by Host1 to Host2 will enter switch port F0/1 and exit switch port F0/2. All FastEthernet ports on the switch are access ports in VL AN 5. A network analyzer connects to port F0/9. A network engineer wants to use SPAN to direct traffic to the network analyzer. Which one answer is the best answer for what traffic to direct to the analyzer with SPAN, if the goal is to gather all traffic sent between Host1 and Host2, but to avoid gathering multiple copies of the same frames? a. Use a SPAN source VLAN of VLAN 5 for both directions of traffic. b. Use a SPAN source port of F0/1 for the transmit direction of traffic. c. Use a SPAN source port of F0/2 for both directions of traffic. d. Use a SPAN source port of both F0/1 and F0/2 for both directions of traffic.

7. C. The requirements in the question ask that you gather all traffic sent between Host1 and Host2, to avoid gathering extra copies of the same frame. That requirement means you need to capture frames sent from Host1 to Host2, and frames sent from Host2 back to Host1. It also means that the solution should not capture the same frame multiple times. Each incorrect answer either gathers too little traffic, or gathers the required traffic but also more traffic than the correct answer would gather. First, the answer of collecting from F0/1 for a single (transmit) direction is incorrect because it gathers too little traffic. Frames sent by Host2 to Host1 would arrive in switch port F0/2 and then be sent out port F0/1 to Host1, and would be copied by the SPAN session. However, frames sent by Host1 would be received on switch port F0/1, and would not be copied by that SPAN session. The answer about using VLAN 5 as a source would work, but because all FastEthernet ports on the switch are in VLAN 5, this option gathers more traffic than is necessary. The answer about using F0/2 as the source, for both directions of traffic, is correct. It will copy all frames sent by Host1 to Host2 (frames that the switch transmits out port F0/2), as well as frames sent by Host2 to Host1 (which will be frames received on switch port F0/2). This option does gather frames sent between Host2 and other hosts as well. The final incorrect answer refers to collecting traffic from both F0/1 and F0/2, but in both directions. That option would gather all frames sent between Host1 and Host2 twice, which would work, but the question asked that you gather no more traffic than is required.

7. What STP feature causes an interface to be placed in the forwarding state as soon as the interface is physically active? a. STP b. EtherChannel c. Root Guard d. PortFast

7. D. The PortFast feature allows STP to move a port from blocking to forwarding, without going through the interim listening and learning states. STP allows this exception when the link is known to have no switch on the other end of the link, removing the risk of a switching loop. BPDU Guard is a common feature to use at the same time as PortFast, because it watches for incoming bridge protocol data units (BPDU), which should not happen on an access port, and prevents the loops from a rogue switch by disabling the port.

8. Which of the following are allowed when configuring Local SPAN sessions? (Choose two answers.) a. Using more than one SPAN source port in one SPAN session b. Using a SPAN source port and SPAN source VLAN in one SPAN session c. Using an EtherChannel port as a SPAN source port d. Using one SPAN destination port in two different SPAN sessions Foundation Topics

8. A, C. Local SPAN has a variety of configuration dependencies. Each Local SPAN session can have multiple sources, but they must be either interfaces or VLANs, and not a mix. Source ports can include both access and trunk ports as well as EtherChannel interfaces. Finally, each SPAN destination port can be used in only one SPAN session at the same time. To reuse that destination port, you must first unconfigure the destination port from the original SPAN session (no monitor session destination) and then configure it to be part of another SPAN session.

6. Examine the output. Which of the following statements are true based on the output of this show command from Router R1? (Choose two answers.) R1# show ip bgp summary BGP router identifier 2.2.2.2, local AS number 101 BGP table version is 1, main routing table version 1 Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 1.1.1.1 4 201 2 2 1 0 0 00:00:37 1 a. Neighbor 1.1.1.1 is an eBGP peer. b. The TCP connection needed by BGP is not working at this point. c. R1 has sent one prefi x to neighbor 1.1.1.1. d. R1 has a neighbor 1.1.1.1 remote-as 201 command confi gured.

A, D. The one BGP peer listed on R1, 1.1.1.1, is an eBGP peer. The line that lists 1.1.1.1 also lists the peer's ASN (201). The first line of output lists R1's ASN (101), so with different ASNs, the peer is an eBGP peer. The line that lists the peer (1.1.1.1) basically relists the information in the neighbor 1.1.1.1 remote-as 201 command in two of the first three items in that line. The state of this peer is established, which is the final BGP state, after the TCP connection is established and the BGP peers have agreed that their parameters match and they can exchange routes. The state is known by virtue of a number being listed on the far right in the "State/PfxRcd" column. That same column lists 1, meaning R1 has received or learned one prefix from this peer—not that R1 has sent one prefix to this peer.