51-100 ccna

What are the possible trunking modes for a switch port? (Choose three.) - transparent - auto - on - desirable - client - forwarding

- auto - on - desirable

Which are valid modes for a switch port used as a VLAN trunk? (Choose three.) - transparent - auto -on - desirable - blocking - forwarding

- auto - on - desirable

Which term describes a spanning-tree network that has all switch ports in either the blocking or fowarding state? - converged - redundant - provisioned - spanned

- converged Spanning Tree Protocol convergence (Layer 2 convergence) happens when bridges and switches have transitioned to either the forwarding or blocking state. When layer 2 is converged, root bridge is elected and all port roles (Root, Designated and Non-Designated) in all switches are selected.

Which of these represents an IPv6 link-local address? A. FE80::380e:611a:e14f:3d69 B. FE81::280f:512b:e14f:3d69 C. FEFE:0345:5f1b::e14d:3d69 D. FE08::280e:611:a:f14f:3d69

A. FE80::380e:611a:e14f:3d69 Explanation: In the Internet Protocol Version 6 (IPv6), the address block fe80::/10 has been reserved for link- local unicast addressing. The actual link local addresses are assigned with the prefix fe80::/64. They may be assigned by automatic (stateless) or stateful (e.g. manual) mechanisms.

Which two statements describe characteristics of IPv6 unicast addressing? (Choose two.) A. Global addresses start with 2000::/3. B. Link-local addresses start with FE00:/12. C. Link-local addresses start with FF00::/10. D. There is only one loopback address and it is ::1. E. If a global address is assigned to an interface, then that is the only allowable address for the interface.

A. Global addresses start with 2000::/3. D. There is only one loopback address and it is ::1.

A Cisco router is booting and has just completed the POST process. It is now ready to find and load an IOS image. What function does the router perform next? A. It checks the configuration register. B. It attempts to boot from a TFTP server. C. It loads the first image file in flash memory. D. It inspects the configuration file in NVRAM for boot instructions.

A. It checks the configuration register. Explanation: Default (normal) Boot SequencePower on Router - Router does POST - Bootstrap starts IOS load - Check configuration registerto see what mode the router should boot up in (usually 0x2102 to read startup-config in NVRAM / or 0x2142 to start in "setup-mode") - check the startup-config file in NVRAM for boot-system commands - load IOS from Flash.

What are three approaches that are used when migrating from an IPv4 addressing scheme to an IPv6 scheme. (Choose three.) A. enable dual-stack routing B. configure IPv6 directly C. configure IPv4 tunnels between IPv6 islands D. use proxying and translation to translate IPv6 packets into IPv4 packets E. statically map IPv4 addresses to IPv6 addresses F. use DHCPv6 to map IPv4 addresses to IPv6 addresses

A. enable dual-stack routing C. configure IPv4 tunnels between IPv6 islands D. use proxying and translation to translate IPv6 packets into IPv4 packets Explanation: Several methods are used terms of migration including tunneling, translators, and dual stack. Tunnels are used to carry one protocol inside another, while translators simply translate IPv6 packets into IPv4 packets. Dual stack uses a combination of both native IPv4 and IPv6. With dual stack, devices are able to run IPv4 and IPv6 together and if IPv6 communication is possible that is the preferred protocol. Hosts can simultaneously reach IPv4 and IPv6 content.

The network administrator has been asked to give reasons for moving from IPv4 to IPv6. What are two valid reasons for adopting IPv6 over IPv4? (Choose two.) A. no broadcast B. change of source address in the IPv6 header C. change of destination address in the IPv6 header D. Telnet access does not require a password E. autoconfiguration F. NAT

A. no broadcast E. autoconfiguration IPv6 does not use broadcasts, and autoconfiguration is a feature of IPV6 that allows for hosts to automatically obtain an IPv6 address.

Which two benefits are provided by using a hierarchical addressing network addressing scheme? (Choose two.) A. reduces routing table entries B. auto-negotiation of media rates C. efficient utilization of MAC addresses D. dedicated communications between devices E. ease of management and troubleshooting

A. reduces routing table entries E. ease of management and troubleshooting

Which command displays CPU utilization? A. show protocols B. show process C. show system D. show version

B. show process

Which two of these are characteristics of the 802.1Q protocol? (Choose two.) - It is used exclusively for tagging VLAN frames and does not address network reconvergence following switched network topology changes. - It modifies the 802.3 frame header, and thus requires that the FCS be recomputed. - It is a Layer 2 messaging protocol which maintains VLAN configurations across networks. - It includes an 8-bit field which specifies the priority of a frame. - It is a trunking protocol capable of carrying untagged frames.

- It modifies the 802.3 frame header, and thus requires that the FCS be recomputed. - It is a trunking protocol capable of carrying untagged frames. Explanation: 802.1Q protocol, or Virtual Bridged Local Area Networks protocol, mainly stipulates the realization of the VLAN. 802.1Q is a standardized relay method that inserts 4 bytes field into the original Ethernet frame and re-calculate the FCS. 802.1Q frame relay supports two types of frame: marked and non-marked. Non-marked frame carries no VLAN identification information.

Three switches are connected to one another via trunk ports. Assuming the default switch configuration, which switch is elected as the root bridge for the spanning-tree instance of VLAN 1? - the switch with the highest MAC address - the switch with the lowest MAC address - the switch with the highest IP address - the switch with the lowest IP address

- the switch with the lowest MAC address Explanation: Each switch in your network will have a Bridge ID Priority value, more commonly referred to as a BID. This BID is a combination of a default priority value and the switch's MAC address, with the priority value listed first. The lowest BID will win the election process. For example, if a Cisco switch has the default priority value of 32,768 and a MAC address of 11- 22-33-44-55-66, the BID would be 32768:11-22-33-44-55-66. Therefore, if the switch priority is left at the default, the MAC address is the deciding factor in the root bridge election.

Which command can you use to manually assign a static IPv6 address to a router interface? A. ipv6 autoconfig 2001:db8:2222:7272::72/64 B. ipv6 address 2001:db8:2222:7272::72/64 C. ipv6 address PREFIX_1 ::1/64 D. ipv6 autoconfig

B. ipv6 address 2001:db8:2222:7272::72/64 Explanation: To assign an IPv6 address to an interface, use the "ipv6 address" command and specify the IP address you wish to use.

Which three are characteristics of an IPv6 anycast address? (Choose three.) A. one-to-many communication model B. one-to-nearest communication model C. any-to-many communication model D. a unique IPv6 address for each device in the group E. the same address for multiple devices in the group F. delivery of packets to the group interface that is closest to the sending device

B. one-to-nearest communication model E. the same address for multiple devices in the group F. delivery of packets to the group interface that is closest to the sending device Explanation: A new address type made specifically for IPv6 is called the Anycast Address. These IPv6 addresses are global addresses, these addresses can be assigned to more than one interface unlike an IPv6 unicast address. Anycast is designed to send a packet to the nearest interface that is apart of that anycast group. The sender creates a packet and forwards the packet to the anycast address as the destination address which goes to the nearest router. The nearest router or interface is found by using the metric of a routing protocol currently running on the network. However in a LAN setting the nearest interface is found depending on the order the neighbors were learned. The anycast packet in a LAN setting forwards the packet to the neighbor it learned about first.

Which three of these statements regarding 802.1Q trunking are correct? (Choose three.) - 802.1Q native VLAN frames are untagged by default. - 802.1Q trunking ports can also be secure ports. - 802.1Q trunks can use 10 Mb/s Ethernet interfaces. - 802.1Q trunks require full-duplex, point-to-point connectivity. - 802.1Q trunks should have native VLANs that are the same at both ends.

- 802.1Q native VLAN frames are untagged by default. - 802.1Q trunks can use 10 Mb/s Ethernet interfaces. - 802.1Q trunks should have native VLANs that are the same at both ends. Explanation: By default, 802.1Q trunk defined Native VLAN in order to forward unmarked frame. Switches can forward Layer 2 frame from Native VLAN on unmarked trunks port. Receiver switches will transmit all unmarked packets to Native VLAN. Native VLAN is the default VLAN configuration of port. Note for the 802.1Q trunk ports between two devices, the same Native VLAN configuration is required on both sides of the link. If the Native VLAN in 802.1Q trunk ports on same trunk link is properly configured, it could lead to layer 2 loops. The 802.1Q trunk link transmits VLAN information through Ethernet.

What is one benefit of PVST+? - PVST+ supports Layer 3 load balancing without loops. - PVST+ reduces the CPU cycles for all the switches in the network. -PVST+ allows the root switch location to be optimized per VLAN. - PVST+ automatically selects the root bridge location, to provide optimized bandwidth usage.

- PVST+ allows the root switch location to be optimized per VLAN. Explanation: The PVST+ provides Layer 2 load-balancing for the VLAN on which it runs. You can create different logical topologies by using the VLANs on your network to ensure that all of your links are used but that no one link is oversubscribed. Each instance of PVST+ on a VLAN has a single root switch. This root switch propagates the spanning-tree information associated with that VLAN to all other switches in the network. Because each switch has the same information about the network, this process ensures that the network topology is maintained and optimized per VLAN.

Which two of these statements regarding RSTP are correct? (Choose two.) - RSTP cannot operate with PVST+. - RSTP defines new port roles. - RSTP defines no new port states. - RSTP is a proprietary implementation of IEEE 802.1D STP. - RSTP is compatible with the original IEEE 802.1D STP.

- RSTP defines new port roles. - RSTP is compatible with the original IEEE 802.1D STP. When network topology changes, rapid spanning tree protocol (IEEE802.1W, referred to as RSTP) will speed up significantly the speed to re-calculate spanning tree. RSTP not only defines the role of other ports: alternative port and backup port, but also defines status of 3 ports: discarding status, learning status, forwarding status. RSTP is 802.1D standard evolution, not revolution. It retains most of the parameters, and makes no changes.

What are three advantages of VLANs? (Choose three.) - VLANs establish broadcast domains in switched networks. - VLANs utilize packet filtering to enhance network security. - VLANs provide a method of conserving IP addresses in large networks. -VLANs provide a low-latency internetworking alternative to routed networks. - VLANs allow access to network services based on department, not physical location. - VLANs can greatly simplify adding, moving, or changing hosts on the network.

- VLANs establish broadcast domains in switched networks. - VLANs allow access to network services based on department, not physical location. - VLANs can greatly simplify adding, moving, or changing hosts on the network. Explanation: VLAN technology is often used in practice, because it can better control layer2 broadcast to improve network security. This makes network more flexible and scalable. Packet filtering is a function of firewall instead of VLAN.

What two things will a router do when running a distance vector routing protocol? (Choose two.) A. Send periodic updates regardless of topology changes. B. Send entire routing table to all routers in the routing domain. C. Use the shortest-path algorithm to the determine best path. D. Update the routing table based on updates from their neighbors. E. Maintain the topology of the entire network in its database.

A. Send periodic updates regardless of topology changes. D. Update the routing table based on updates from their neighbors. Explanation: Distance means how far and Vector means in which direction. Distance Vector routing protocols pass periodic copies of routing table to neighbor routers and accumulate distance vectors. In distance vector routing protocols, routers discover the best path to destination from each neighbor. The routing updates proceed step by step from router to router.

On a corporate network, hosts on the same VLAN can communicate with each other, but they are unable to communicate with hosts on different VLANs. What is needed to allow communication between the VLANs? A. a router with subinterfaces configured on the physical interface that is connected to the switch B. a router with an IP address on the physical interface connected to the switch C. a switch with an access link that is configured between the switches D. a switch with a trunk link that is configured between the switches

A. a router with subinterfaces configured on the physical interface that is connected to the switch Explanation: Different VLANs can't communicate with each other , they can communicate with the help of Layer3 router. Hence , it is needed to connect a router to a switch , then make the sub-interface on the router to connect to the switch, establishing Trunking links to achieve communications of devices which belong to different VLANs. When using VLANs in networks that have multiple interconnected switches, you need to use VLAN trunking between the switches. With VLAN trunking, the switches tag each frame sent between switches so that the receiving switch knows to what VLAN the frame belongs. End user devices connect to switch ports that provide simple connectivity to a single VLAN each. The attached devices are unaware of any VLAN structure. By default, only hosts that are members of the same VLAN can communicate. To change this and allow inter-VLAN communication, you need a router or a layer 3 switch. Here is the example of configuring the router for inter-vlan communication RouterA(config)#int f0/0.1 RouterA(config-subif)#encapsulation ? dot1Q IEEE 802.1Q Virtual LAN RouterA(config-subif)#encapsulation dot1Q or isl VLAN ID RouterA(config-subif)# ip address x.x.x.x y.y.y.y

A national retail chain needs to design an IP addressing scheme to support a nationwide network. The company needs a minimum of 300 sub-networks and a maximum of 50 host addresses per subnet. Working with only one Class B address, which of the following subnet masks will support an appropriate addressing scheme? (Choose two.) A. 255.255.255.0 B. 255.255.255.128 C. 255.255.252.0 D. 255.255.255.224 E. 255.255.255.192 F. 255.255.248.0

B. 255.255.255.128 E. 255.255.255.192 Explanation: Subnetting is used to break the network into smaller more efficient subnets to prevent excessive rates of Ethernet packet collision in a large network. Such subnets can be arranged hierarchically, with the organization's network address space (see also Autonomous System) partitioned into a tree-like structure. Routers are used to manage traffic and constitute borders between subnets. A routing prefix is the sequence of leading bits of an IP address that precede the portion of the address used as host identifier. In IPv4 networks, the routing prefix is often expressed as a "subnet mask", which is a bit mask covering the number of bits used in the prefix. An IPv4 subnet mask is frequently expressed in quad-dotted decimal representation, e.g., 255.255.255.0 is the subnet mask for the 192.168.1.0 network with a 24-bit routing prefix (192.168.1.0/24).

Which IPv6 address is the all-router multicast group? A. FF02::1 B. FF02::2 C. FF02::3 D. FF02::4

B. FF02::2 Explanation: Well-known IPv6 multicast addresses: Address Description ff02::1 All nodes on the local network segment ff02::2 All routers on the local network segment

Which parameter would you tune to affect the selection of a static route as a backup, when a dynamic protocol is also being used? A. hop count B. administrative distance C. link bandwidth D. link delay E. link cost

B. administrative distance Explanation: By default the administrative distance of a static route is 1, meaning it will be preferred over all dynamic routing protocols. If you want to have the dynamic routing protocol used and have the static route be used only as a backup, you need to increase the AD of the static route so that it is higher than the dynamic routing protocol.

An administrator must assign static IP addresses to the servers in a network. For network 192.168.20.24/29, the router is assigned the first usable host address while the sales server is given the last usable host address. Which of the following should be entered into the IP properties box for the sales server? A. IP address: 192.168.20.14 Subnet Mask: 255.255.255.248 Default Gateway: 192.168.20.9 B. IP address: 192.168.20.254 Subnet Mask: 255.255.255.0 Default Gateway: 192.168.20.1 C. IP address: 192.168.20.30 Subnet Mask: 255.255.255.248 Default Gateway: 192.168.20.25 D. IP address: 192.168.20.30 Subnet Mask: 255.255.255.240 Default Gateway: 192.168.20.17 E. IP address: 192.168.20.30 Subnet Mask: 255.255.255.240 Default Gateway: 192.168.20.25

C. IP address: 192.168.20.30 Subnet Mask: 255.255.255.248 Default Gateway: 192.168.20.25 For the 192.168.20.24/29 network, the usable hosts are 192.168.24.25 (router) ?192.168.24.30 (used for the sales server).

If IP routing is enabled, which two commands set the gateway of last resort to the default gateway? (Choose two.) A. ip default-gateway 0.0.0.0 B. ip route 172.16.2.1 0.0.0.0 0.0.0.0 C. ip default-network 0.0.0.0 D. ip default-route 0.0.0.0 0.0.0.0 172.16.2.1 E. ip route 0.0.0.0 0.0.0.0 172.16.2.1

C. ip default-network 0.0.0.0 E. ip route 0.0.0.0 0.0.0.0 172.16.2.1 Explanation: Both the "ip default-network" and "ip route 0.0.0.0 0.0.0.0 (next hop)" commands can be used to set the default gateway in a Cisco router.

The network administrator is asked to configure 113 point-to-point links. Which IP addressing scheme defines the address range and subnet mask that meet the requirement and waste the fewest subnet and host addresses? A. 10.10.0.0/16 subnetted with mask 255.255.255.252 B. 10.10.0.0/18 subnetted with mask 255.255.255.252 C. 10.10.1.0/24 subnetted with mask 255.255.255.252 D. 10.10.0.0/23 subnetted with mask 255.255.255.252 E. 10.10.1.0/25 subnetted with mask 255.255.255.252

D. 10.10.0.0/23 subnetted with mask 255.255.255.252 Explanation: We need 113 point-to-point links which equal to 113 sub-networks < 128 so we need to borrow 7 bits (because 2^7 = 128). The network used for point-to-point connection should be /30. So our initial network should be 30 ?7 = 23. So 10.10.0.0/23 is the correct answer. You can understand it more clearly when writing it in binary form: /23 = 1111 1111.1111 1110.0000 0000 /30 = 1111 1111.1111 1111.1111 1100 (borrow 7 bits)

How many bits are contained in each field of an IPv6 address? A. 24 B. 4 C. 8 D. 16

D. 16 An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits (two octets). The groups are separated by colons (:). An example of an IPv6 address is 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

Which option is a valid IPv6 address? A. 2001:0000:130F::099a::12a B. 2002:7654:A1AD:61:81AF:CCC1 C. FEC0:ABCD:WXYZ:0067::2A4 D. 2004:1:25A4:886F::1

D. 2004:1:25A4:886F::1 Explanation: An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits (two octets). The groups are separated by colons (:). An example of an IPv6 address is 2001:0db8:85a3:0000:0000:8a2e:0370:7334. The leading 0's in a group can be collapsed using ::, but this can only be done once in an IP address.

Which IPv6 address is valid? A. 2001:0db8:0000:130F:0000:0000:08GC:140B B. 2001:0db8:0:130H::87C:140B C. 2031::130F::9C0:876A:130B D. 2031:0:130F::9C0:876A:130B

D. 2031:0:130F::9C0:876A:130B Explanation: An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits (two octets). The groups are separated by colons (:). An example of an IPv6 address is 2001:0db8:85a3:0000:0000:8a2e:0370:7334. The leading 0's in a group can be collapsed using ::, but this can only be done once in an IP address.

Which subnet mask would be appropriate for a network address range to be subnetted for up to eight LANs, with each LAN containing 5 to 26 hosts? A. 0.0.0.240 B. 255.255.255.252 C. 255.255.255.0 D. 255.255.255.224 E. 255.255.255.240

D. 255.255.255.224 Explanation: For a class C network, a mask of 255.255.255.224 will allow for up to 8 networks with 32 IP addresses each (30 usable).

What is the alternative notation for the IPv6 address B514:82C3:0000:0000:0029:EC7A:0000:EC72? A. B514 : 82C3 : 0029 : EC7A : EC72 B. B514 : 82C3 :: 0029 : EC7A : EC72 C. B514 : 82C3 : 0029 :: EC7A : 0000 : EC72 D. B514 : 82C3 :: 0029 : EC7A : 0 : EC72

D. B514 : 82C3 :: 0029 : EC7A : 0 : EC72 There are two ways that an IPv6 address can be additionally compressed: compressing leading zeros and substituting a group of consecutive zeros with a single double colon (::). Both of these can be used in any number of combinations to notate the same address. It is important to note that the double colon (::) can only be used once within a single IPv6 address notation. So, the extra 0's can only be compressed once.

How is an EUI-64 format interface ID created from a 48-bit MAC address? A. by appending 0xFF to the MAC address B. by prefixing the MAC address with 0xFFEE C. by prefixing the MAC address with 0xFF and appending 0xFF to it D. by inserting 0xFFFE between the upper three bytes and the lower three bytes of the MAC address E. by prefixing the MAC address with 0xF and inserting 0xF after each of its first three bytes

D. by inserting 0xFFFE between the upper three bytes and the lower three bytes of the MAC address Explanation: The modified EUI-64 format interface identifier is derived from the 48-bit link-layer (MAC) address by inserting the hexadecimal number FFFE between the upper three bytes (OUI field) and the lower three bytes (serial number) of the link layer address.

Which command is used to display the collection of OSPF link states? A. show ip ospf link-state B. show ip ospf lsa database C. show ip ospf neighbors D. show ip ospf database

D. show ip ospf database