SWITCH

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What command would configure the aging time for all MAC addresses?

switch(config)#mac-address-table aging-time [sec] [vlan]

What is the size of the VLAN field inside an 802.1q frame? A. 8-bit B. 12-bit C. 16-bit D 32-bit

12-bit The VLAN field is a 12-bit field specifying the VLAN to which the frame belongs. The hexadecimal values of 0x000 and 0xFFF are reserved. All other values may be used as VLAN identifiers, allowing up to 4,094 VLANs

In a Cisco switch, what is the default period of time after which a MAC address ages out and is discarded? A. 100 seconds B. 180 seconds C. 300 seconds D. 600 seconds

300 seconds To configure the aging time for all MAC addresses, perform this task: Command Purpose Step 1 switch#configure terminal Enters configuration mode. Step 2 switch(config)#mac-address-table aging-timeseconds[vlanvlan_id] Specifies the time before an entry ages out and is discarded from the MAC address table. The range is from 0 to 1000000;the default is 300 seconds. Entering the value 0 disables the MAC aging. If a VLAN is not specified, the aging specification applies to all VLANs.

Which statement about using EtherChannel on Cisco IOS switches is true? A. A switch can support up to eight compatibly configured Ethernet interfaces in an EtherChannel. The EtherChannel provides full-duplex bandwidth up to 800 Mbps only for Fast EtherChannel or 8 Gbps only for Gigabit EtherChannel. B. A switch can support up to 10 compatibly configured Ethernet interfaces in an EtherChannel. The EtherChannel provides full-duplex bandwidth up to 1000 Mbps only for Fast EtherChannel or 8 Gbps only for Gigabit EtherChannel. C. A switch can support up to eight compatibly configured Ethernet interfaces in an EtherChannel. The EtherChannel provides full-duplex bandwidth up to 800 Mbps only for Fast EtherChannel or 16 Gbps only for Gigabit EtherChannel. D. A switch can support up to 10 compatibly configured Ethernet interfaces in an EtherChannel. The EtherChannel provides full-duplex bandwidth up to 1000 Mbps only for Fast EtherChannel or 10 Gbps only for Gigabit EtherChannel.

A An EtherChannel consists of individual Fast Ethernet or Gigabit Ethernet links bundled into a single logical link. The EtherChannel provides full-duplex bandwidth up to 800 Mbps (Fast EtherChannel) or 8 Gbps (Gigabit EtherChannel) between your switch and another switch or host. Each EtherChannel can consist of up to eight compatibly configured Ethernet interfaces. All interfaces in each EtherChannel must be the same speed, and all must be configured as either Layer 2 or Layer 3 interfaces.

After reviewing UDLD status on switch ports, an engineer notices that the current bidirectional state for an access port is "Unknown." Which statement describes what this indicates about the status of the port? A. The port is fully operational and no known issues are detected. B. The bidirectional status of "unknown" indicates that the port will go into the disabled state because it stopped receiving UDLD packets from its neighbor. C. UDLD moved into aggressive mode after inconsistent acknowledgements were detected. D. The UDLD port is placed in the "unknown" state for 5 seconds until the next UDLD packet is received on the interface.

A By default, UDLD is disabled on all interfaces. We can enable UDLD globally on the device, or individually on specific interfaces with the command udld port. This enables UDLD in normal mode. It would be prohibitively difficult to coordinate the configuration of UDLD on both ends of a link at the same time, so when UDLD is first enabled and does not detect a neighbor the link state is considered unknown, which is not necessarily an error condition. The port will remain operational during this time. When UDLD is finally enabled on the other end, the status will transitionto bidirectional.

While doing network discovery using Cisco Discovery Protocol, it is found that rapid error tracking is not currently enabled. Which option must be enabled to allow for enhanced reporting mechanisms using Cisco Discovery Protocol? A. Cisco Discovery Protocol version 2 B. Cisco IOS Embedded Event Manager C. logging buffered D. Cisco Discovery Protocol source interface E. Cisco Discovery Protocol logging options

A CDP Version 1 -- This is the first version of CDP which was used for the discovery of Cisco devices in the network. This version is mainly used for backward compatibility. CDP Version 2 -- This is the most recent version of CDP which has enhanced features such as rapid reporting mechanism, which is used to track down errors and minimize costly downtime. It allows you to track instances even if the native VLAN ID or port duplex states do not match between connecting devices. This is the default version on all switches.

Which statement about Cisco Discovery Protocol configuration on a Cisco switch is true? A. CDP is enabled by default and can be disabled globally with the command no cdp run. B. CDP is disabled by default and can be enabled globally with the command cdp enable. C. CDP is enabled by default and can be disabled globally with the command no cdp enable. D. CDP is disabled by default and can be enabled globally with the command cdp run.

A CDP is enabled on your router by default, which means the Cisco IOS software will receive CDP information. CDP also is enabled on supported interfaces by default. To disable CDP on an interface, use the "no cdp enable interface" configuration command. To disable it globally, use the "no cdp run" command.

Which statement about using native VLANs to carry untagged frames is true? A. Cisco Discovery Protocol version 2 carries native VLAN information, but version 1 does not. B. Cisco Discovery Protocol version 1 carries native VLAN information, but version 2 does not. C. Cisco Discovery Protocol version 1 and version 2 carry native VLAN information. D. Cisco Discovery Protocol version 3 carries native VLAN information, but versions 1 and 2 do not.

A Cisco Discovery Protocol (CDP) version 2 passes native VLAN information between Cisco switches. If you have a native VLAN mismatch, you will see CDP error messages on the console output.

A network engineer must improve bandwidth and resource utilization on the switches by stopping the inefficient flooding of frames on trunk ports where the frames are not needed. Which Cisco IOS feature can be used to achieve this task? A. VTP pruning B. access list C. switchport trunk allowed VLAN D. VLAN access-map

A Cisco advocates the benefits of pruning VLANs in order to reduce unnecessary frame flooding. The"vtp pruning"command prunes VLANs automatically, which stops the inefficient flooding of frames where they are not needed.

Which statement about Cisco devices learning about each other through Cisco Discovery Protocol is true? A. Each device sends periodic advertisements to multicast address 01:00:0C:CC:CC:CC. B. Each device broadcasts periodic advertisements to all of its neighbors. C. Each device sends periodic advertisements to a central device that builds the network topology. D. Each device sends periodic advertisements to all IP addresses in its ARP table.

A Cisco devices send periodic CDP announcements to the multicast destination address 01-00-0ccc- cc-cc, out each connected network interface. These multicast packets may be received by Cisco switches and other networking devices that support CDP into their connected network interface.

Which command does a network engineer use to verify the spanning-tree status for VLAN 10? A. switch# show spanning-tree vlan 10 B. switch# show spanning-tree bridge C. switch# show spanning-tree brief D. switch# show spanning-tree summary E. switch# show spanning-tree vlan 10 brief

A Command Description show spanning-tree Displays information about the spanning-tree state. Example output: SW2#show spanning-tree vlan 10 VLAN0010 Spanning tree enabled protocol rstp Root ID Priority 24586 Address 0014.f2d2.4180 Cost 9 Port 216 (Port-channel21) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32778 (priority 32768 sys-id-ext 10) Address 001c.57d8.9000 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 sec Interface Role Sts Cost Prio.Nbr Type ------------------ ---- --- --------- -------- --------------------------- Po21 Root FWD 9 128.216 P2p Po23 Altn BLK 9 128.232 P2p

What happens on a Cisco switch that runs Cisco IOS when an RSTP-configured switch receives 802.1d BPDU? A. 802.1d does not understand RSTP BPDUs because they are different versions, but when a RSTP switch receives an 802.1d BPDU, it responds with an802.1d BPDU and eventually the two switches run 802.1d to communicate. B. 802.1d understands RSTP BPDUs because they are the same version, but when a RSTP switch receives a 802.1d BPDU, it responds with a 802.1d BPDU and eventually the two switches run 802.1d to communicate. C. 802.1d does not understand RSTP BPDUs because they are different versions, but when a RSTP switch receives a 802.1d BPDU, it does not respond with a 802.1d BPDU. D. 802.1d understands RSTP BPDUs because they are the same version, but when a RSTP switch receives a 802.1d BPDU, it does not respond with a 802.1d BPDU and eventually the two switches run 802.1d to communicate.

A For backward compatibility with 802.1D switches, RSTP selectively sends 802.1D configuration BPDUs and TCN BPDUs on a per-port basis. When a port is initialized, the migrate-delay timer is started (specifies the minimum time during which RSTP BPDUs are sent), and RSTP BPDUs are sent. While this timer is active, the switch processes all BPDUs received on that port and ignores the protocol type. If the switch receives an 802.1D BPDU after the port migration-delay timer has expired, it assumes that it is connected to an 802.1D switch and starts using only 802.1D BPDUs. However, if the RSTP switch is using 802.1D BPDUs on a port and receives an RSTP BPDU after the timer has expired, it restarts the timer and starts using RSTP BPDUs on that port.

In which portion of the frame is the 802.1q header found? A. within the Ethernet header B. within the Ethernet payload C. within the Ethernet FCS D. within the Ethernet source MAC address

A Frame format Insertion of 802.1Q tag in an Ethernet frame 802.1Q does not encapsulate the original frame. Instead, for Ethernet frames, it adds a 32-bit field between the source MAC address and the EtherType/length fields of the original frame

After an EtherChannel is configured between two Cisco switches, interface port channel 1 is in the down/down state. Switch A is configured with channel-group 1 mode active, while Switch B is configured with channel-group 1 mode desirable. Why is the EtherChannel bundle not working? A. The switches are using mismatched EtherChannel negotiation modes. B. The switch ports are not configured in trunking mode. C. LACP priority must be configured on both switches. D. The channel group identifier must be different for Switch A and Switch B.

A Here we have a situation where one switch is using active mode, which is an LACP mode, and the other is using desirable, which is a PAGP mode. You can not mix the LACP and PAGP protocols to form an etherchannel. Here is a summary of the various etherchannel modes: EtherChannel PAgP Modes Mode Description auto Places a port into a passive negotiating state, in which the port responds to PAgP packets it receives but does not start PAgP packet negotiation. This setting minimizes the transmission of PAgP packets. This mode is not supported when the EtherChannel members are from different switches in the switch stack (cross-stack EtherChannel). desirable Places a port into an active negotiating state, in which the port starts negotiations with other ports by sending PAgP packets. This mode is not supported when the EtherChannel members are from different switches in the switch stack (cross-stack EtherChannel). EtherChannel LACP Modes Mode Description active Places a port into an active negotiating state in which the port starts negotiations with other ports by sending LACP packets. passive Places a port into a passive negotiating state in which the port responds toLACP packets that it receives, but does not start LACP packet negotiation. This setting minimizes the transmission of LACP packets.

A network engineer notices inconsistent Cisco Discovery Protocol neighbors according to the diagram that is provided. The engineer notices only a single neighbor that uses Cisco Discovery Protocol, but it has several routing neighbor relationships. What would cause the output to show only the single neighbor? A. The routers are connected via a Layer 2 switch. B. IP routing is disabled on neighboring devices. C. Cisco Express Forwarding is enabled locally. D. Cisco Discovery Protocol advertisements are inconsistent between the local and remote devices.

A If all of the routers are connected to each other using a layer 2 switch, then each router will only have the single switch port that it connects to as its neighbor. Even though multiple routing neighbors can be formed over a layer 2 network, only the physical port that it connects to will be seen as a CDP neighbor. CDP can be used to determine the physical topology, but not necessarily the logical topology.

Which option describes a limitation of LLDP? A. LLDP cannot provide information about VTP. B. LLDP does not support TLVs. C. LLDP can discover only Windows servers. D. LLDP can discover up to two devices per port.

A LLDP Versus Cisco Discovery Protocol TLV Comparison Function Description LLDP TLV Cisco Discovery Protocol TLV IP network prefix support-Used to send the network prefix and used for ODR No IP Network Prefix TLV Hello piggybacking-Can be used to piggy back hello messages from other protocols No Protocol Hello TLV Maximum-transmission-unit (MTU) support-Specifies the size of the MTU No MTU TLV External port support-Used to identify the card terminating the fiber in the case of wavelengthdivision multiplexing (WDM) No External Port-ID TLV VTP management support No VTP Management Domain TLV Port unidirectional mode-Used in fiber, where the connection may be unidirectional No Port UniDirectional Mode TLV Management address Management Address TLV Management-AddressTLV Allows for organizational unique TLVs Yes No

Which feature must be enabled to eliminate the broadcasting of all unknown traffic to switches that are not participating in the specific VLAN? A. VTP pruning B. port-security C. storm control D. bpdguard

A VTP ensures that all switches in the VTP domain are aware of all VLANs. However, there are occasions when VTP can create unnecessary traffic. All unknown unicasts and broadcasts in a VLAN are flooded over the entire VLAN. All switches in the network receive all broadcasts, even in situations in which few users are connected in that VLAN. VTP pruning is a feature that you use in order to eliminate or prune this unnecessary traffic.

Which statement about LLDP-MED is true? A. LLDP-MED is an extension to LLDP that operates between endpoint devices and network devices. B. LLDP-MED is an extension to LLDP that operates only between network devices. C. LLDP-MED is an extension to LLDP that operates only between endpoint devices. D. LLDP-MED is an extension to LLDP that operates between routers that run BGP.

A LLDP for Media Endpoint Devices (LLDP-MED) is an extension to LLDP that operates between endpoint devices such as IP phones and network devices such as switches. It specifically provides support for voice over IP (VoIP) applications and provides additional TLVs for capabilities discovery, network policy, Power over Ethernet, and inventory management.

A network engineer changed the port speed and duplex setting of an existing EtherChannel bundle that uses the PAgP protocol. Which statement describes what happens to all ports in the bundle? A. PAgP changes the port speed and duplex for all ports in the bundle. B. PAgP drops the ports that do not match the configuration. C. PAgP does not change the port speed and duplex for all ports in the bundle until the switch is rebooted. D. PAgP changes the port speed but not the duplex for all ports in the bundle.

A PAgP aids in the automatic creation of EtherChannel links. PAgP packets are sent between EtherChannel-capable ports in order to negotiate the formation of a channel. Some restrictions are deliberately introduced into PAgP. The restrictions are: PAgP does not form a bundle on ports that are configured for dynamic VLANs. PAgP requires that all ports in the channel belong to the same VLAN or are configured as trunk ports. When a bundle already exists and a VLAN of a port is modified, all ports in the bundle are modified to match that VLAN. PAgP does not group ports that operate at different speeds or port duplex. If speed and duplex change when a bundle exists, PAgP changes the port speed and duplex for all ports in the bundle. PAgP modes are off, auto, desirable, and on. Only the combinations auto-desirable, desirabledesirable, and on-on allow the formation of a channel. The device on the other side must have PAgP set to on if a device on one side of the channel does not support PAgP, such as a router.

Which statement about the use of PAgP link aggregation on a Cisco switch that is running Cisco IOS Software is true? A. PAgP modes are off, auto, desirable, and on. Only the combinations auto-desirable, desirabledesirable, and on-on allow the formation of a channel. B. PAgP modes are active, desirable, and on. Only the combinations active-desirable, desirabledesirable, and on-on allow the formation of a channel. C. PAgP modes are active, desirable, and on. Only the combinations active-active, desirabledesirable, and on-on allow the formation of a channel. D. PAgP modes are off, active, desirable, and on. Only the combinations auto-auto, desirabledesirable, and on-on allow the formation of a channel.

A PAgP modes are off, auto, desirable, and on. Only the combinations auto-desirable, desirable-desirable, and on-on will allow a channel to be formed. The PAgP modes are explained below. Only the combinations of auto-desirable, desirable-desirable, and on-on will allow a channel to be formed. If a device on one side of the channel does not support PAgP, such as a router, the device on the other side must have PAgP set to on.

After the recent upgrade of the switching infrastructure, the network engineer notices that the port roles that were once "blocking" are now defined as "alternate" and "backup." What is the reason for this change? A. The new switches are using RSTP instead of legacy IEEE 802.1D STP. B. IEEE 802.1D STP and PortFast have been configured by default on all newly implemented Cisco Catalyst switches. C. The administrator has defined the switch as the root in the STP domain. D. The port roles have been adjusted based on the interface bandwidth and timers of the new Cisco Catalyst switches.

A RSTP works by adding an alternative port and a backup port compared to STP. These ports are allowed to immediately enter the forwarding state rather than passively wait for the network to converge. RSTP bridge port roles: * Root port - A forwarding port that is the closest to the root bridge in terms of path cost * Designated port - A forwarding port for every LAN segment * Alternate port - A best alternate path to the root bridge. This path is different than using the root port. The alternative port moves to the forwarding state if there is a failure on the designated port for the segment. * Backup port - A backup/redundant path to a segment where another bridge port already connects. The backup port applies only when a single switch has two links to the same segment (collision domain). To have two links to the same collision domain, the switch must be attached to a hub. * Disabled port - Not strictly part of STP, a network administrator can manually disable a port

A network engineer wants to add a new switch to an existing switch stack. Which configuration must be added to the new switch before it can be added to the switch stack? A. No configuration must be added. B. stack ID C. IP address D. VLAN information E. VTP information

A Switch Stack Offline Configuration You can use the offline configuration feature toprovision(to supply a configuration to) a new switch before it joins the switch stack. You can configure in advance the stack member number, the switch type, and the interfaces associated with a switch that is not currently part of the stack. The configuration that you create on the switch stack is called the provisioned configuration. The switch that is added to the switch stack and that receives this configuration is called theprovisioned switch. You manually create the provisioned configuration through theswitchstackmember- numberprovisiontypeglobal configuration command. The provisioned configuration is automatically created when a switch is added to a switch stack and when no provisioned configuration exists. When you configure the interfaces associated with a provisioned switch (for example, as part of a VLAN), the switch stack accepts the configuration, and the information appears in the running configuration. The interface associated with the provisioned switch is not active, operates as if it is administratively shut down, and theno shutdowninterface configuration command does not return it to active service. The interface associated with the provisioned switch does not appear in the display of the specific feature; for example, it does not appear in theshow vlanuser EXEC command output. The switch stack retains the provisioned configuration in the running configuration whether or not the provisioned switch is part of the stack. You can save the provisioned configuration to the startup configuration file by entering thecopy running-config startup- configprivileged EXEC command. The startup configuration file ensures that the switch stack can reload and can use the saved information whether or not the provisioned switch is part of the switch stack. Effects of Adding a Provisioned Switch to a Switch Stack When you add a provisioned switch to the switch stack, the stack applies either the provisioned configuration or the default configuration.Table 5-1lists the events that occur when the switch stack compares the provisioned configuration with the provisioned switch.

The network manager has requested that several new VLANs (VLAN 10, 20, and 30) are allowed to traverse the switch trunk interface. After the command switchport trunk allowed vlan 10,20,30 is issued, all other existing VLANs no longer pass traffic over the trunk. What is the root cause of the problem? A. The command effectively removed all other working VLANs and replaced them with the new VLANs. B. VTP pruning removed all unused VLANs. C. ISL was unable to encapsulate more than the already permitted VLANs across the trunk. D. Allowing additional VLANs across the trunk introduced a loop in the network.

A The "switchport trunk allowed vlan" command will only allow the specified VLANs, and overwrite any others that were previously defined. You would also need to explicitly allow the other working VLANs to this configuration command, or use the "issue the switchport trunkallowed vlan add vlan-list" command instead to add these 3 VLANS to the other defined allowed VLANs.

Which statement about the UDLD protocol is true? A. UDLD is a Cisco-proprietary Layer 2 protocol that enables devices to monitor the physical status of links and detect unidirectional failures. B. UDLD is a Cisco-proprietary Layer 2 protocol that enables devices to advertise their identity, capabilities, and neighbors on a local area network. C. UDLD is a standardized Layer 2 protocol that enables devices to monitor the physical status of links and detect unidirectional failures. D. UDLD is a standardized Layer 2 protocol that enables devices to advertise their identity, capabilities, and neighbors on a local area network.

A The Cisco-proprietary UDLD protocol monitors the physical configuration of the links between devices and ports that support UDLD. UDLD detects the existence of unidirectional links. When a unidirectional link is detected, UDLD puts the affected port into the errdisabled state and alerts the user.

Refer to the exhibit. Which statement about switch S1 is true? ---------------------------------------------------------------- S1#show etherchannel summary Flags: D-down P-bundled in port-channel I-stand-alone s-suspended H-Hot-standby(LACP only) R-Layer3 S-Layer2 U-in use f-failed to allocate aggregator M-not in use, minimum links not met u-unsuitable for bundling w-waiting to be aggregated d-default port Number of channel-groups in use: 1 Number of aggregators: 1 Group Port-channel Protocol Ports ------+------------------+--------------+------------------------- 1 Po1(SU) LACP Fa0/13(P) Fa0/14(P) Fa0/15(P) A. Physical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 2 port-channel interface using an open standard protocol. B. Logical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 2 physical port- channel interface using a Cisco proprietary protocol. C. Physical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 3 port-channel interface using a Cisco proprietary protocol. D. Logical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 3 physical port- channel interface using an open standard protocol.

A These three ports show that they are in Port Channel 1, and the (SU) means they are in use and operating at layer 2. The protocol used for this port channel shows as LACP, which is a standards based protocol, as opposed to PAgP, which is Cisco proprietary.

Which SDM template is the most appropriate for a Layer 2 switch that provides connectivity to a large number of clients? A. VLAN B. default C. access D. routing

A To allocate ternary content addressable memory (TCAM) resources for different usages, the switch SDM templates prioritize system resources to optimize support for certain features. You can select SDM templates to optimize these features: Access--The access template maximizes system resources for access control lists (ACLs) to accommodate a large number of ACLs. Default--The default template gives balance to all functions. Routing--The routing template maximizes system resources for IPv4 unicast routing, typically required for a router or aggregator in the center of a network. VLANs--The VLAN template disables routing and supports the maximum number of unicast MAC addresses (clients). It would typically be selected for a Layer 2 switch.

Which SDM template disables routing and supports the maximum number of unicast MAC addresses? A. VLAN B. access C. default D. routing

A To allocate ternary content addressable memory (TCAM) resources for different usages, the switch SDM templates prioritize system resources to optimize support for certain features. You can select SDM templates to optimize these features: Access--The access template maximizes system resources for access control lists (ACLs) to accommodate a large number of ACLs. Default--The default template gives balance to all functions. Routing--The routing template maximizes system resources for IPv4 unicast routing, typically required for a router or aggregator in the center of a network. VLANs--The VLAN template disables routing and supports the maximum number of unicast MAC addresses. It would typically be selected for a Layer 2 switch.

If a network engineer applies the command mac-address-table notification mac-move on a Cisco switch port, whenis a syslog message generated? A. A MAC address or host moves between different switch ports. B. A new MAC address is added to the content-addressable memory. C. A new MAC address is removed from the content-addressable memory. D. More than 64 MAC addresses are added to the content-addressable memory.

A To enable MAC-move notification, use themac-address-table notification mac-move command in global configuration mode. To disable MAC-move notification, use thenoform of this command. mac-address-table notification mac-move[counter[syslog]] no mac-address-table notification mac-move[counter[syslog]] Syntax Description counter (Optional) Specifies the MAC-move counter feature. syslog (Optional) Specifies the syslogging facility when the MAC-move notification detects the first instance of the MAC move. Usage Guidelines MAC-move notification generates a syslog message whenever a MAC address or host moves between different switch ports.

Which option lists the information that is contained in a Cisco Discovery Protocol advertisement? A. native VLAN IDs, port-duplex, hardware platform B. native VLAN IDs, port-duplex, memory errors C. native VLAN IDs, memory errors, hardware platform D. port-duplex, hardware platform, memory errors

A Type-Length-Value fields (TLVs) are blocks of information embedded in CDP advertisements. Table 21 summarizes the TLV definitions for CDP advertisements. Table 21Type-Length-Value Definitions for CDPv2 TLV Definition Device-ID TLV Identifies the device name in the form of a character string. Address TLV Contains a list of network addresses of both receiving and sending devices. Port-ID TLV Identifies the port on which the CDP packet is sent. Capabilities TLV Describes the functional capability for the device in the form of a device type, for example, a switch. Version TLV Contains information about the software release version on which the device is running. Platform TLV Describes the hardware platform name of the device, for example, Cisco 4500. IP Network Prefix TLV Contains a list of network prefixes to which the sending device can forward IP packets. This information is in the form of the interfaceprotocol and port number, for example, Eth 1/0. VTP Management Domain TLV Advertises the system's configured VTP management domain name-string. Used by network operators to verify VTP domain configuration in adjacent network nodes. Native VLAN TLV Indicates, per interface, the assumed VLAN for untagged packets on the interface. CDP learns the native VLAN for an interface. This feature is implemented only for interfaces that support the IEEE 802.1Q protocol. Full/Half Duplex TLV Indicates status (duplex configuration) of CDP broadcast interface. Used by network operators to diagnose connectivity problems between adjacent network elements.

Switch A, B, and C are trunked together and have been properly configured for VTP. Switch C receives VLAN information from the VTP server Switch A, but Switch B does not receive any VLAN information. What is the most probable cause of this behavior? ------------------------------------------------------------- Switch A <--> Switch B <--> Switch C ------------------------------------------------------------- A. Switch B is configured in transparent mode. B. Switch B is configured with an access port to Switch A, while Switch C is configured with a trunk port to Switch B. C. The VTP revision number of the Switch B is higher than that of Switch A. D. The trunk between Switch A and Switch B is misconfigured.

A VTP transparent switches do not participate in VTP. A VTP transparent switch does not advertise its VLAN configuration and does not synchronize its VLAN configuration based on received advertisements, but transparent switches do forward VTP advertisements that they receive out their trunk ports in VTP Version 2.

Which feature is automatically enabled when a voice VLAN is configured, but not automatically disabled when a voice VLAN is removed? Which feature is automatically enabled when a voice VLAN is configured, but not automatically disabled when a voice VLAN is removed?

A Which feature is automatically enabled when a voice VLAN is configured, but not automatically disabled when a voice VLAN is removed?

What effect does the mac address-table aging-time 180 command have on the MAC addresstable? A. This is how long a dynamic MAC address will remain in the CAM table. B. The MAC address-table will be flushed every 3 minutes. C. The default timeout period will be 360 seconds. D. ARP requests will be processed less frequently by the switch. E. The MAC address-table will hold addresses 180 seconds longer than the default of 10 minutes.

A You can configure the amount of time that an entry (the packet source MAC address and port that packet ingresses) remain in the MAC table. To configure the aging time for all MAC addresses, perform this task: Command Purpose Step 1 switch#configure terminal Enters configuration mode. Step 2 switch(config)#mac-address-table aging-timeseconds[vlanvlan_id] Specifies the time before an entry ages out and is discarded from the MAC address table. The range is from 0 to 1000000; the default is 300 seconds. Entering the value 0 disables the MAC aging. If a VLAN is not specified, theaging specification applies to all VLANs. This example shows how to set the aging time for entries in the MAC address table to 600 seconds (10 minutes): switch#configure terminal switch(config)#mac-address-table aging-time 600

Which statement about the use of SDM templates in a Cisco switch is true? A. SDM templates are used to configure system resources in the switch to optimize support for specific features, depending on how the switch is used in the network. B. SDM templates are used to create Layer 3 interfaces (switch virtual interfaces) to permit hosts in one VLAN to communicate with hosts in another VLAN. C. SDM templates are used to configure ACLs that protect networks and specific hosts from unnecessary or unwanted traffic. D. SDM templates are used to configure a set of ACLs that allows the users to manage the flow of traffic handled by the route processor. E. SDM templates are configured by accessing the switch using the web interface.

A You can use SDM templates to configure system resources in the switch to optimize support for specific features, depending on how the switch is used in the network. You can select a template to provide maximum system usage for some functions; for example, use the default template to balance resources, and use access template to obtain maximum ACL usage. To allocate hardware resources for different usages, the switch SDM templates prioritize system resources to optimize support for certain features.

A network engineer must adjust the STP interface attributes to influence root port selection. Which two elements are used to accomplish this? (Choose two.) A. port-priority B. cost C. forward-timers D. link type E. root guard

AB Spanning tree forces redundant data paths into a standby (blocked) state. If a network segment in the spanning tree fails and a redundant path exists, the spanning-tree algorithm recalculates the spanning-tree topology and activates the standby path. Switches send and receive spanning-tree frames, called bridge protocol data units (BPDUs), at regular intervals. The switches do not forward these frames but use them to construct a loop-free path. BPDUs contain informationabout the sending switch and its ports, including switch and MAC addresses, switch priority, port priority, and path cost. Spanning tree uses this information to elect the root switch and root port for the switched network and the root port and designated port for each switched segment. When two ports on a switch are part of a loop, the spanning-tree port priority and path cost settings control which port is put in the forwarding state and which is put in the blocking state. The spanning-tree port priority value represents the location of a port in the network topology and how well it is located to pass traffic. The path cost value represents the media speed.

For security reasons, the IT manager has prohibited users from dynamically establishing trunks with their associated upstream switch. Which two actions can prevent interface trunking? A. Configure trunk and access interfaces manually. B. Disable DTP on a per interface basis. C. Apply BPDU guard and BPDU filter. D. Enable switchport block on access ports.

AB The Dynamic Trunking Protocol (DTP) is used to negotiate forming a trunk between two Cisco devices. DTP causes increased traffic, and is enabled by default, but may be disabled. To disable DTP, configure "switchport nonegotiate." This prevents the interface from generating DTP frames.You can use this command only when the interface switchport mode is access or trunk. You must manually configure the neighboring interface as a trunk interface to establish a trunk link, otherwise the link will be a non-trunking link.

A network engineer configured a fault-tolerance link on Gigabit Ethernet links G0/1, G0/2, G0/3, and G0/4 between two switches using Ethernet port-channel. Which action allows interface G0/1 to always actively forward traffic in the port-channel? A. Configure G0/1 as half duplex and G0/2 as full duplex. B. Configure LACP port-priority on G0/1 to 1. C. Configure LACP port-priority on G0/1 to 65535. D. LACP traffic goes through G0/4 because it is the highest interface ID.

B A LACP port priority is configured on each port using LACP. The port priority can be configured automatically or through the CLI. LACP uses the port priority with the port number to form the port identifier. The port priority determines which ports should be put in standby mode whenthere is a hardware limitation that prevents all compatible ports from aggregating. The higher the number, the lower the priority. The valid range is from 1 to 65535. The default is 32768.

What is the maximum number of VLANs that can be assigned to an access switchport without a voice VLAN? A. 0 B. 1 C. 2 D. 1024

B A standard (non-voice VLAN port) access switch port can belong to only a single VLAN. If more than one VLAN is needed, the port should be configured as a trunk port.

What is the default interval at which Cisco devices send Cisco Discovery Protocol advertisements? A. 30 seconds B. 60 seconds C. 120 seconds D. 300 seconds

B Cisco Discovery Protocol is a Layer 2, media-independent, and network-independent protocol that networking applications use to learn about nearby, directly connected devices. Cisco Discovery Protocol is enabled by default. Each device configured for Cisco Discovery Protocol advertises at least one address at which the device can receive messages and sends periodic advertisements (messages) to the well-known multicast address 01:00:0C:CC:CC:CC. Devices discover each other by listening at that address. They also listen to messages to learn when interfaces on other devices are up or go down. Advertisements contain time-to-live information, which indicates the length of time a receiving device should hold Cisco Discovery Protocol information before discarding it. Advertisements supported and configured in Cisco software are sent, by default, every 60 seconds.

Which statement describes what happens when a switch enters dual active recovery mode? A. The switch shuts down and waits for the VSL link to be restored before sending traffic. B. All interfaces are shut down in the formerly active virtual switch member, but the new active virtual switch forwards traffic on all links. C. The switch continues to forward traffic out all links and enables spanning tree on VSL link and all other links to prevent loops. D. The VSS detects which system was last in active state and shuts down the other switch.

B In the dual active recovery mode, all interfaces except the VSL interfaces are in an operationally shut down state in the formerly active virtual switch member. The new active virtual switch continues to forward traffic on all links.

A network engineer has just deployed a non-Cisco device in the network and wants to get information about it from a connected device. Cisco Discovery Protocol is not supported, so the open standard protocol must be configured. Which protocol does the network engineer configure on both devices to accomplish this? A. IRDP B. LLDP C. NDP D. LLTD

B The Link Layer Discovery Protocol (LLDP) is a vendor-neutral link layer protocol in the Internet Protocol Suite used by network devices for advertising their identity, capabilities, and neighbors on an IEEE 802 local area network, principally wired Ethernet. LLDP performs functions similar to several proprietary protocols, such as the Cisco Discovery Protocol (CDP).

After the implementation of several different types of switches from different vendors, a network engineer notices that directly connected devices that use Cisco Discovery Protocol are not visible. Which vendor-neutral protocol could be used to resolve this issue? A. Local Area Mobility B. Link Layer Discovery Protocol C. NetFlow D. Directed Response Protocol Correct

What is required for a LAN switch to support 802.1q Q-in-Q encapsulation? A. Support less than 1500 MTU B. Support 1504 MTU or higher C. Support 1522 layer 3 IP and IPX packet D. Support 1547 MTU only

B The default system MTU for traffic on Catalyst switches is 1500 bytes. Because the 802.1Q tunneling(Q-in-Q)feature increases the frame size by 4 bytes when the extra tag is added, you must configure all switches in the service-provider network to be able to process maximum frames by increasing the switch system MTU size to at least 1504 bytes.

While working in the core network building, a technician accidently bumps the fiber connection between two core switches and damages one of the pairs of fiber. As designed, the link was placed into a non-forwarding state due to a fault with UDLD. After the damaged cable was replaced, the link did not recover. What solution allows the network switch to automatically recover from such an issue? A. macros B. errdisable autorecovery C. IP Event Dampening D. command aliases E. Bidirectional Forwarding Detection

B There are a number of events which can disable a link on a Catalyst switch, such as the detection of a loopback, UDLD failure, or a broadcast storm. By default, manual intervention by an administrator is necessary to restore the interface to working order; this can be done by issuing shutdown followed by no shutdown on the interface. The idea behind requiring administrative action is so that a human engineer can intercede, assess, and (ideally) correct the issue. However, some configurations may be prone to accidental violations, and a steady recurrence of these can amount to a huge time sink for the administrative staff. This is where errdisable autorecovery can be of great assistance. We can configure the switch to automatically re-enable any error-disabled interfaces after a specified timeout period. This gives the offending issue a chance to be cleared by the user (for example, by removing an unapproved device) without the need for administrative intervention.

After configuring new data VLANs 1020 through 1030 on the VTP server, a network engineer notices that none of the VTP clients are receiving the updates. What is the problem? A. The VTP server must be reloaded. B. The VTP version number must be set to version 3. C. After each update to the VTP server, it takes up to 4 hours propagate. D. VTP must be stopped and restarted on the server. E. Another switch in the domain has a higher revision number than the server.

B VTP version 3 supports these features that are not supported in version 1 or version 2: Enhanced authentication--You can configure the authentication as hidden or secret. When hidden, the secret key from the password string is saved in the VLAN database file, but it does not appear in plain text in the configuration. Instead, the key associated with the password is saved in hexadecimal format in the running configuration. You must reenter the password if you enter a takeover command in the domain. When you enter the secret keyword, you can directly configure the password secret key. Support for extended range VLAN (VLANs 1006 to 4094) database propagation. VTP versions 1 and 2 propagate only VLANs 1 to 1005. If extended VLANs are configured, you cannot convert from VTP version 3 to version 1 or 2.

When you design a switched network using VTPv2, how many VLANs can be used to carry user traffic? A. 1000 B. 1001 C. 1024 D. 2048 E. 4095 F. 4096

B VTP versions 1 and 2 Supports normal VLAN numbers (1-1001). Only VTP version 3 supports extended VLANs (1-4095).

After UDLD is implemented, a Network Administrator noticed that one port stops receiving UDLD packets. This port continues to reestablish until after eight failed retries. The port then transitions into the errdisable state. Which option describes what causes the port to go into the errdisable state? A. Normal UDLD operations that prevent traffic loops. B. UDLD port is configured in aggressive mode. C. UDLD is enabled globally. D. UDLD timers are inconsistent.

B With UDLD aggressive mode enabled, when a port on a bidirectional link that has a UDLD neighbor relationship established stops receiving UDLD packets, UDLD tries to reestablish the connection with the neighbor. After eight failed retries, the port is disabled.

An access switch has been configured with an EtherChannel port. After configuring SPAN to monitor this port, the network administrator notices that not all traffic is being replicated to the management server. What is a cause for this issue? A. VLAN filters are required to ensure traffic mirrors effectively. B. SPAN encapsulation replication must be enabled to capture EtherChannel destination traffic. C. The port channel can be used as a SPAN source, but not a destination. D. RSPAN must be used to capture EtherChannel bidirectional traffic.

C A source port or EtherChannel is a port or EtherChannel monitored for traffic analysis. You can configure both Layer 2 and Layer 3 ports and EtherChannels as SPAN sources. SPAN canmonitor one or more source ports or EtherChannels in a single SPAN session. You can configure ports or EtherChannels in any VLAN as SPAN sources. Trunk ports or EtherChannels can be configured as sources and mixed with nontrunk sources. A port- channel interface (an EtherChannel) can be a SPAN source, but not a destination.

What is the default value for the errdisable recovery interval in a Cisco switch? A. 30 seconds B. 100 seconds C. 300 seconds D. 600 seconds

C After you fix the root problem, the ports are still disabled if you have not configured errdisable recovery on the switch. In this case, you must reenable the ports manually. Issue the shutdown command and then the no shutdown interface mode command on the associated interface in order to manually reenable the ports. The errdisable recovery command allows you to choose the type of errors that automatically reenable the ports after a specified amount of time. Theshow errdisable recoverycommand shows the default error-disable recovery state for all the possible conditions. cat6knative#show errdisable recovery ErrDisable Reason Timer Status ---------------- -------------- udld Disabled bpduguard Disabled security-violatio Disabled channel-misconfig Disabled pagp-flap Disabled dtp-flap Disabled link-flap Disabled l2ptguard Disabled psecure-violation Disabled gbic-invalid Disabled dhcp-rate-limit Disabled mac-limit Disabled unicast-flood Disabled arp-inspection Disabled Timer interval: 300 seconds Interfaces that will be enabled at the next timeout: Note: The default timeout interval is 300 secondsand, by default, the timeout feature is disabled.

A new network that consists of several switches has been connected together via trunking interfaces. If all switches currently have the default VTP domain name "null", which statement describes what happens when a domain name is configured on one of the switches? A. The switch with the non-default domain name restores back to "null" upon reboot. B. Switches with higher revision numbers does not accept the new domain name. C. VTP summary advertisements are sent out of all ports with the new domain name. D. All other switches with the default domain name become VTP clients.

C By default, a switch will have a domain name of NULL and no password. If the switch hears a VTP advertisement it will automatically learn the VTP domain name, VLANs, and the configuration revision number. Summary advertisements ?sent out every 300 seconds and every time a change occurs on the VLAN database. Contained in a summary advertisement: VTP version Domain name Configuration revision number Time stamp MD5 encryption hash code

Which technique allows specific VLANs to be strictly permitted by the administrator? A. VTP pruning B. transparent bridging C. trunkallowed VLANs D. VLAN access-list E. L2P tunneling

C By default, a trunk port sends traffic to and receives traffic from all VLANs. All VLAN IDs, 1 to 4094, are allowed on each trunk. However, you can remove VLANs from the allowed list, preventing traffic from those VLANs from passing over the trunk. To restrict the traffic a trunk carries, use the "switchport trunk allowed vlan remove vlan-list" interface configuration command to remove specific VLANs from the allowed list.

A network engineer must implement Ethernet links that are capable of transporting frames and IP traffic for different broadcast domains that are mutually isolated. Consider that this is a multivendor environment. Which Cisco IOS switching feature can be used to achieve the task? A. PPP encapsulation with a virtual template B. Link Aggregation Protocol at the access layer C. dot1q VLAN trunking D. Inter-Switch Link

C Here the question asks for transporting "frames and IP traffic for different broadcast domains that are mutually isolated" which is basically a long way of saying VLANs so trunking is needed to carry VLAN information. There are 2 different methods for trunking, 802.1Q and ISL. Of these, only 802.1Q is supported by multiple vendors since ISL is a Cisco proprietary protocol.

What are the different modes for PAgP?

auto and desirable

Refer to the exhibit. A multilayer switch has been configured to send and receive encapsulated and tagged frames. VLAN 2013 on the multilayer switch is configured as the native VLAN. Which option is the cause of the spanning-tree error? SW-1#sh logging %SPANTREE-SP-2-RECV_PVID-ERR:Received BPDU with inconsistent peer Vlan id 1 on GigabitEthernet11/2 VLAN2013. %SPANTREE-SP-2-BLOCK_PVID_PEER:Blocking GigabitEthernet11/2 on VLAN0001. Inconsistent peer vlan. A. VLAN spanning-tree in SW-2 is configured. B. spanning-tree bpdu-filter is enabled. C. 802.1q trunks are on both sides, both with native VLAN mismatch. D. VLAN ID 1 should not be used for management traffic because its unsafe.

C Here we see that the native VLAN has been configured as 2013 on one switch, but 1 (the default native VLAN) on the other switch. If you use 802.1Q trunks, you must ensure that you choose a common native VLAN for each port in the trunk. Failure to do this causes Cisco switches to partially shut down the trunk port because having mismatched native VLANs can result in spanning-tree loops. Native VLAN mismatches are detected via spanning tree and Cisco Discovery Protocol (CDP), not via DTP messages. If spanning tree detects a native VLAN mismatch, spanning tree blocks local native VLAN traffic and the remote switch native VLAN traffic on the trunk; however, the trunk still remains up for other VLANs.

Which action allows a network engineer to limit a default VLAN from being propagated across all trunks? A. Upgrade to VTP version 3 for advanced feature set support. B. Enable VTP pruning on the VTP server. C. Manually prune default VLAN with switchport trunk allowed vlans remove. D. Use trunk pruning vlan 1.

C Manaully pruning the default VLAN (1) can only be done with the "switchport trunk allowed vlans remove" command. VLAN 1 is not VTP pruning eligible so it cannot be done via VTP pruning. The "trunk pruning vlan 1" option is not a valid command.

A network engineer is setting up a new switched network. The network is expected to grow and add many new VLANs in the future. Which Spanning Tree Protocol should be used to reduce switch resources and managerial burdens that are associated with multiple spanning-tree instances? A. RSTP B. PVST C. MST D. PVST+ E. RPVST+

C Multiple Spanning Tree (MST) extends the IEEE 802.1w RST algorithm to multiple spanning trees. The main purpose of MST is to reduce the total number of spanning-tree instances to match the physical topology of the network and thus reduce the CPU cycles of a switch. PVRST+ runs STP instances for each VLAN and does not take into consideration the physical topology that might not require many different STP topologies. MST, on the other hand, uses a minimum number of STP instances to match the number of physical topologies present.

Refer to the exhibit. The users in an engineering department that connect to the same access switch cannot access the network. The network engineer found that the engineering VLAN is missing from the database. Which action resolves this problem? ----------------------------------------------------------------- Switch1(config)# vlan10 VTP vlan configuration not allowed when device is in CLIENT mode. Switch1# show interfaces trunk Switch1# ------------------------------------------------------------------ A. Disable VTP pruning and disable 802.1q. B. Update the VTP revision number. C. Change VTP mode to server and enable 802.1q. D. Enable VTP pruning and disable 802.1q.

C Only VTP servers can add new VLANs to the switched network, so to enable vlan 10 on this switch you will first need to change the VTP mode from client to server. Then, you will need to enable 802.1Q trunking to pass this new VLAN along to the other switches.

What percentage of bandwidth is reduced when a stack cable is broken? A. 0 B. 25 C. 50 D. 75 E. 100

C Physical Sequential Linkage The switches are physically connected sequentially, as shown in Figure 3. A break in any one of the cables will result in the stack bandwidth being reduced to half of its full capacity. Subsecond timing mechanisms detect traffic problems and immediately institute failover. This mechanism restores dual path flow when the timing mechanisms detect renewed activity on the cable.

A network engineer deployed a switch that operates the LAN base feature set and decides to use the SDM VLAN template. The SDM template is causing the CPU of the switch to spike during peak working hours. What is the root cause of this issue? A. The VLAN receives additional frames from neighboring switches. B. The SDM VLAN template causes the MAC address-table to overflow. C. The VLAN template disables routing in hardware. D. The switch needs to be rebooted before the SDM template takes effect.

C SDM Template Notes: All templates are predefined. There is no way to edit template category individual values. The switch reload is required to use a new SDM template. The ACL merge algorithm, as opposed to the original access control entries (ACEs) configured by the user, generate the number of TCAM entries listed for security and QoS ACEs. The first eight lines (up to Security ACEs) represent approximate hardware boundaries set when a template is used. If the boundary is exceeded, all processing overflow is sent to the CPU which can have a major impact on the performance of the switch. Choosing the VLAN template will actually disable routing (number of entry for unicast or multicast route is zero) in hardware.

Refer to the exhibit. The network switches for two companies have been connected and manually configured for the required VLANs, but users in company A are not able to access network resources in company B when DTP is enabled. Which action resolves this problem? ------------------------------------------------------------------ Company A# show vtp status VTP Version :2 Configuration Revision :0 Maximum VLANs supported locally :1005 Number of existing VLANs :9 VTP Operating Mode :Server VTP Domain Name :company VTP Pruning Mode :Disabled VTP V2 Mode :Disabled VTP Traps Generation :Disabled Company B# show vtp status VTP Version :2 Configuration Revision :0 Maximum VLANs supported locally :1005 Number of existing VLANs :42 VTP Operating Mode :Server VTP Domain Name :company VTP Pruning Mode :Disabled VTP V2 Mode :Disabled VTP Traps Generation :Disabled ---------------------------------------------------------------- A. Delete vlan.dat and ensure that the switch with lowest MAC address is the VTP server. B. Disable DTP and document the VTP domain mismatch. C. Manually force trunking with switchport mode trunk on both switches. D. Enable the company B switch with the vtp mode server command.

C Since the number of existing VLANs differ on the switches (9 on A and 42 on B) we know that there is a problem with VTP or the trunking interfaces. The VTP domain names do match and they are both VTP servers so there are no issues there. The only viable solution is that there is a DTP issues and so you must instead manually configure the trunk ports between these two switches so that the VLAN information can be sent to each switch.

What is the maximum number of 10 Gigabit Ethernet connections that can be utilized in an EtherChannel for the virtual switch link? A. 4 B. 6 C. 8 D. 12

C The VSS is made up of the following: Virtual switch members: Cisco Catalyst 6500 Series Switches (up to two switches with initial release) deployed with the Virtual Switching Supervisor 720 10GE Virtual switch link (VSL): 10 Gigabit Ethernet connections (up to eight using EtherChannel) between the virtual switch members.

Refer to the exhibit. How can the traffic that is mirrored out the GigabitEthernet0/48 port be limited to only traffic that is received or transmitted in VLAN 10 on the GigabitEthernet0/1 port? ------------------------------------------------------------- interface GigabitEthernet0/1 switchport switchport mode trunk switchport trunk allowed vlan 1-100 ! interface GigabitEthernet0/48 switchport switchport mode access ! monitor session 1 source interface GigabitEthernet0/1 monitor session 1 destination interface GigabitEthernet0/48 ------------------------------------------------------------- A. Change the configuration for GigabitEthernet0/48 so that it is a member of VLAN 10. B. Add an access list to GigabitEthernet0/48 to filter out traffic that is not in VLAN 10. C. Apply the monitor session filter globally to allow only traffic from VLAN 10. D. Change the monitor session source to VLAN 10 instead of the physical interface.

C To start a new flow-based SPAN (FSPAN) session or flow-based RSPAN (FRSPAN) source or destination session, or to limit (filter) SPAN source traffic to specific VLANs, use the monitor session filter global configuration command. Usage Guidelines You can set a combined maximum of two local SPAN sessions and RSPAN source sessions. You can have a total of 66 SPAN and RSPAN sessions on a switch or switch stack. You can monitor traffic on a single VLAN or on a series or range of ports or VLANs. You select a series or range of VLANs by using the [ , | -] options. If you specify a series of VLANs, you must enter a space before and after the comma. If you specify a range of VLANs, you must enter a space before and after the hyphen ( -). VLAN filtering refers to analyzing network traffic on a selected set of VLANs on trunk source ports. By default, all VLANs are monitored on trunk source ports. You can use the monitor session session_number filter vlan vlan-id command to limit SPAN traffic on trunk source ports to only the specified VLANs. VLAN monitoring and VLAN filtering are mutually exclusive. If a VLAN is a source, VLAN filtering cannot be enabled. If VLAN filtering is configured, a VLAN cannot become a source.

When two MST instances (MST 1 and MST 2) are created on a switch, what is the total number of spanning-tree instances running on the switch? A. 1 B. 2 C. 3 D. 4

C Unlike other spanning tree protocols, in which all the spanning tree instances are independent, MST establishes and maintains IST, CIST, and CST spanning trees: Within each MST region, MST maintains multiple spanning tree instances. Instance 0 is a special instance for a region, known as the IST. All other MST instances are numbered from 1 to 4094.In the case for this question, there will be the 2 defined MST instances, and the special 0 instance, for a total of 3 instances. The IST is the only spanning tree instance that sends and receives BPDUs. All of the other spanning tree instance information is contained in MSTP records (M-records), which are encapsulated within MST BPDUs. Because the MST BPDU carries information for all instances, the number of BPDUs that need to be processed to support multiple spanning tree instances is significantly reduced. All MST instances within the same region share the same protocol timers, but each MST instance has its own topology parameters, such as root bridge ID, root path cost, and so forth. By default, all VLANs are assigned to the IST. An MST instance is local to the region; for example, MST instance 1 in region A is independent of MST instance 1 in region B, even if regions A and B are interconnected. A CIST is a collection of the ISTs in each MST region. The CST interconnects the MST regions and single spanning trees.

Which technique automatically limits VLAN traffic to only the switches that require it? A. access lists B. DTP in nonegotiate C. VTP pruning D. PBR

C VTP pruning enhances network bandwidth use by reducing unnecessary flooded traffic, such as broadcast, multicast, unknown, and flooded unicast packets to only the switches that require it. VTP pruning increases available bandwidth by restricting flooded traffic to those trunk links that the traffic must use to access the appropriate network devices. By default, VTP pruning is disabled.

Which VLAN range is eligible to be pruned when a network engineer enables VTP pruning on a switch? A. VLANs 1-1001 B. VLANs 1-4094 C. VLANs 2-1001 D. VLANs 2-4094

C VTP pruning should only be enabled on VTP servers, all the clients in the VTP domain will automatically enable VTP pruning. By default, VLANs 2 ?1001 are pruning eligible, but VLAN 1 can't be pruned because it's an administrative VLAN. Both VTP versions 1 and 2 supports pruning.

Which statement about restrictions for multichassis LACP is true? A. It is available only on a Cisco Catalyst 6500 Series chassis. B. It does not support 1Gb links. C. Converting a port channel to mLACP can cause a service disruption. D. It is not available in VSS.

C When configuring mLACP for Server Access, follow these guidelines and restrictions: PFC3A mode does not support the mLACP for server access feature. VSS mode does not support the mLACP for server access feature. No more than 100 VLANs can be active on a switch configured as a PoA. mLACP does not support half-duplex links. mLACP does not support multiple neighbors. Converting a port channel to mLACP can cause a service disruption. The DHD system priority must be lower (higher numerically) than the PoA system priority.

A network engineer is trying to deploy a PC on a network. The engineer observes that when the PC is connected to the network, it takes 30 to 60 seconds for the PC to see any activity on the network interface card. Which Layer 2 enhancement can be used to eliminate this delay? A. Configure port duplex and speed to auto negotiation. B. Configure port to duplex full and speed 1000. C. Configure spanning-tree portfast. D. Configure no switchport.

C When first powered on, each port goes through 4 states to ensure that there are no physical loops in the layer 2 broadcast domain. These steps are outlined as follows. With the initial version of spanning tree, this process could take from 30-60 seconds. 1. Blocking - A port that would cause a switching loop, no user data is sent or received but it may go into forwarding mode if the other links in use were to fail and the spanning tree algorithm determines the port may transition to the forwarding state. BPDU data is still received in blocking state. 2. Listening - The switch processes BPDUs and awaits possible new information that would cause it to return to the blocking state. 3. Learning - While the port does not yet forward frames (packets) it does learn source addresses from frames received and adds them to the filtering database (switching database) 4. Forwarding - A port receiving and sending data, normal operation. STP still monitors incoming BPDUs that would indicate it should return to the blocking state to prevent a loop. STP PortFast causes a Layer 2 LAN interface configured as an access port to enter the forwarding state immediately, bypassing the listening and learning states.

Refer to the exhibit. A network engineer investigates a recent network failure and notices that one of the interfaces on the switch is still down. What is causing the line protocol on this interface to be shown as down? ------------------------------------------------------------- GigabitEthernet0/23 is up, line protocol is down (monitoring) Hardware is C6k 1000mb 802.3, address is 001c.f9d4.7500 (bia 001c.f9d4.750) MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, Reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 1000Mb/s ------------------------------------------------------------- A. There is a layer 1 physical issue. B. There is a speed mismatch on the interface. C. The interface is configured as the target of the SPAN session. D. The interface is configured as the source of the SPAN session. E. There is a duplex mismatch on the interface.

C With the SAPN destination port, the state of the destination port is up/down by design. The interface shows the port in this state in order to make it evident that the port is currently not usable as a production port. This is the normal operational state for SPAN destinations.

Which two protocols can be automatically negotiated between switches for trunking? A. PPP B. DTP C. ISL D. HDLC E. DLCI F. DOT1Q

CF Switches such as the Catalyst 3550 that are capable of either 802.1Q or ISL trunking encapsulation, the switchport trunk encapsulation [dot1q | isl | negotiate] interface command must be used prior to the switchport mode trunk command.

A network engineer tries to configure storm control on an EtherChannel bundle. What is the result of the configuration? A. The storm control settings will appear on the EtherChannel, but not on the associated physical ports. B. The configuration will be rejected because storm control is not supported for EtherChannel. C. The storm control configuration will be accepted, but will only be present on the physical interfaces. D. The settings will be applied to the EtherChannel bundle and all associated physical interfaces.

D After you configure an EtherChannel, any configuration that you apply to the port-channel interface affects the EtherChannel; any configuration that you apply to the physical interfaces affects only the interface where you apply the configuration. Storm Control is an exception to this rule. For example, you cannot configure Storm Control on some of the members of an EtherChannel; Storm Control must be configured on all or none of the ports. If you configure Storm Control on only some of the ports, those ports will be dropped from the EtherChannel interface (put in suspended state). Therefore, you should configure Storm Control at the EtherChannel Interface level, and not at the physical interface level.

Refer to the exhibit. Why would the switch be considered as a root bridge? ------------------------------------------------------------- Root ID Priority 1 Address 0060.47A2.34E8 This bridge is the root Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 1 (priority 0 sys-id-ext 1) Address 0060.47A2.34E8 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 20 Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Fa0/1 Desg FWD 19 128.1 P2p Fa0/3 Desg FWD 19 128.3 P2p Fa0/4 Desg FWD 19 128.4 P2p Fa0/2 Desg FWD 19 128.2 P2p ------------------------------------------------------------- A. The bridge priority is 1 and all ports are forwarding. B. The switch priority for VLAN 1 and the macro specifies "This Bridge is the root". C. The bridge priority is 128.19 and all ports are forwarding. D. The switch priority value is zero, it has the lowest priority value for VLAN 1.

D For priority, the range is 0 to 61440 in increments of 4096; the default is 32768. The lower the number, the more likely the switch will be chosen as the root switch.

Pilot testing of the new switching infrastructure finds that when the root port is lost, STP immediately replaces the root port with an alternative root port. Which spanning-tree technology is used to accomplish backup root port selection? A. PVST+ B. PortFast C. BackboneFast D. UplinkFast E. Loop Guard F. UDLD

D If a switch loses connectivity, it begins using the alternate paths as soon as the spanning tree selects a new root port. By enabling UplinkFast with the spanning-tree uplinkfast global configuration command, you can accelerate the choice of a new root port when a link or switch fails or when the spanning tree reconfigures itself. The root port transitions to the forwarding state immediately without going through the listening and learning states, as it would with the normal spanning-tree procedures. UplinkFast provides fast convergence after a direct link failure and achieves load balancing between redundant Layer 2 links using uplink groups. An uplink group is a set of Layer 2 interfaces (per VLAN), only one of which is forwarding at any given time. Specifically, an uplink group consists of the root port (which is forwarding) and a set of blocked ports, except for selflooping ports. The uplink group provides an alternate path in case the currently forwarding link fails.

For client server failover purposes, the application server team has indicated that they must not have the standard 30 second delay before their switchport enters a forwarding state. For their disaster recovery feature to operate successfully, they require the switchport to enter a forwarding state immediately. Which spanning-tree feature satisfies this requirement? A. Rapid Spanning-Tree B. Spanning-Tree Timers C. Spanning-Tree FastPort D. Spanning-Tree PortFast E. Spanning-Tree Fast Forward

D In order to allow immediate transition of the port into forwarding state, enable the STP PortFast feature. PortFast immediately transitions the port into STP forwarding mode upon linkup. The port still participates in STP. So if the port is to be a part of the loop, the port eventually transitions into STP blocking mode. Example configuration: Switch-C# configure terminal Switch-C(config)# interface range fa0/3 - 24 Switch-C(config-if-range)# spanning-tree portfast

Which statement describes what happens if all VSL connections between the virtual switch members are lost? A. Both virtual switch members cease to forward traffic. B. The VSS transitions to the dual active recovery mode, and both virtual switch members continue to forward traffic independently. C. The virtual switch members reload. D. The VSS transitions to the dual active recovery mode, and only the new active virtual switch continues to forward traffic.

D Q. What happens if all VSL connections between the virtual switch members are lost? A.VSLs can be configured with up to eight links between the two switches across any combination of line cards or supervisor ports to provide a high level of redundancy. If for some rare reason all VSL connections are lost between the virtual switch members leaving both the virtual switch members up, the VSS will transition to the dual active recovery mode. The dual active state is detected rapidly (subsecond) by any of the following three methods: Enhancement to PAgP used in MEC with connecting Cisco switches L3 Bidirectional Forwarding Detection (BFD) configuration on a directly connected link (besides VSL) between virtual switch members or through an L2 link through an access layer switch L2 Fast-Hello Dual-Active Detection configuration on a directly connected link (besides VSL) between virtual switch members (supported with 12.2(33)SXI) In the dual active recovery mode, all interfaces except the VSL interfaces are in an operationally shut down state in the formerly active virtual switch member. The new active virtual switch continues to forward traffic on all links.

Refer to the exhibit. All ports are members of VLAN 10. Considering the default cost of upstream bridges to the root bridge is equal, which option will be the new root port for VLAN 10? ------------------------------------------------------------- Switch# Show run interface FastEthernet0/13 spanning-tree cost 1000 ! interface FastEthernet0/14 spanning-tree cost 1000 ! interface FastEthernet0/15 spanning-tree cost 1000 ! interface FastEthernet0/20 spanning-tree cost 2 ! interface FastEthernet0/21 spanning-tree cost 1 ------------------------------------------------------------- A. interface f0/13 B. interface f0/14 C. interface f0/15 D. interface f0/21

D Root Port election on each bridge Each (non-Root) bridge has exactly one Root Port, which represents the best path to the Root Bridge. In this case, fa0/21 has the lowest cost, so it will be the root port.

Which set of configurations will result in all ports on both switches successfully bundling into an EtherChannel? A. switch1 channel-group 1 mode active switch2 channel-group 1 mode auto B. switch1 channel-group 1 mode desirable switch2 channel-group 1 mode passive C. switch1 channel-group 1 mode on switch2 channel-group 1 mode auto D. switch1 channel-group 1 mode desirable switch2 channel-group 1 mode auto

D The different etherchannel modes are described in the table below: Mode Description active Places an interface into an active negotiating state, in which the interface starts negotiations with other interfaces by sending LACP packets. auto Places an interface into a passive negotiating state, in which the interface responds to PAgP packets it receives but does not start PAgP packet negotiation. This setting minimizes the transmission of PAgP packets. desirable Places an interface into an active negotiating state, in which the interface starts negotiations with other interfaces by sending PAgP packets. on Forces the interface into an EtherChannel without PAgP or LACP. With theonmode, a usable EtherChannel exists only when an interface group in theonmode is connected to another interface group in theonmode. passive Places an interface into a passive negotiating state, in which the interface responds to LACP packets that it receives, but does not start LACP packet negotiation. This setting minimizes the transmission of LACP packets. Both the auto and desirable PAgP modes allow interfaces to negotiate with partner interfaces to determine if they can form an EtherChannel based on criteria such as interface speed and, for Layer 2 EtherChannels, trunking state and VLAN numbers. Interfaces can form an EtherChannel when they are in different PAgP modes as long as the modes are compatible. For example: An interface in the desirable mode can form an EtherChannel with another interface that is in the desirable or auto mode. An interface in the auto mode can form an EtherChannel with another interface in the desirable mode. An interface in the auto mode cannot form an EtherChannel with another interface that is also in the auto mode because neither interface starts PAgP negotiation. An interface in the on mode that is added to a port channel is forced to have the same characteristics as the already existing on mode interfaces in the channel.

Which statement describes what happens when a port configured with root guard receives a superior BPDU? A. The port goes into errdisabled state and stops forwarding traffic. B. The port goes into BPDU-inconsistent state and stops forwarding traffic. C. The port goes into loop-inconsistent state and stops forwarding traffic. D. The port goes into root-inconsistent state and stops forwarding traffic.

D The root guard ensures that the port on which root guard is enabled is the designated port. Normally, root bridge ports are all designated ports, unless two or more ports of the root bridge are connected together. If the bridge receives superior STP Bridge Protocol Data Units (BPDUs) on a root guard-enabled port, root guard moves this port to a root- inconsistent STP state. This root-inconsistent state is effectively equal to a listening state. No traffic is forwarded across this port. In this way, the root guard enforces the position of the root bridge.

What are possible causes for an errdisabled interface? A. routing loop B. cable unplugged C. STP loop guard D. security violation

D There are various reasons for the interface to go into errdisable. The reason can be: Duplex mismatch Port channel misconfiguration BPDU guard violation UniDirectional Link Detection (UDLD) condition Late-collision detection Link-flap detection Security violation Port Aggregation Protocol (PAgP) flap Layer 2 Tunneling Protocol (L2TP) guard DHCP snooping rate-limit Incorrect GBIC / Small Form-Factor Pluggable (SFP) module or cable Address Resolution Protocol (ARP) inspection Inline power

What is the maximum number of switches that can be stacked using Cisco StackWise? A. 4 B. 5 C. 8 D. 9 E. 10 F. 13

D Up to 9 Cisco Catalyst switches can be stacked together to build single logical StackWise switch since Cisco IOS XE Release 3.3.0SE. Prior to Cisco IOS XE Release3.3.0SE, up to 4 Cisco Catalyst switches could be stacked together.

What is the function of NSF? A. forward traffic simultaneously using both supervisors B. forward traffic based on Cisco Express Forwarding C. provide automatic failover to back up supervisor in VSS mode D. provide nonstop forwarding in the event of failure of one of the member supervisors

D VSS is network system virtualization technology that pools multiple Cisco Catalyst 6500 Series Switches into one virtual switch, increasing operational efficiency, boosting nonstop communications, and scaling system bandwidth capacity to 1.4 Tbps. Switches would operate as a single logical virtual switch called a virtual switching system 1440 (VSS1440). VSS formed by two Cisco Catalyst 6500 Series Switches with the Virtual Switching Supervisor 720-10GE. In a VSS, the data plane and switch fabric with capacity of 720 Gbps of supervisor engine in each chassis are active at the same time on both chassis, combining for an active 1400- Gbps switching capacity per VSS. Only one of the virtual switch members has the active control plane. Both chassis are kept in sync with the inter-chassis Stateful Switchover (SSO) mechanism along with Nonstop Forwarding (NSF) to provide nonstop communication even in the event of failure of one of the member supervisor engines or chassis.

Several new switches have been added to the existing network as VTP clients. All of the new switches have been configured with the same VTP domain, password, and version. However, VLANs are not passing from the VTP server (existing network) to the VTP clients. What must be done to fix this? A. Remove the VTP domain name from all switches with "null" and then replace it with the new domain name. B. Configure a different native VLAN on all new switches that are configured as VTP clients. C. Provision one of the new switches to be the VTP server and duplicate information from the existing network. D. Ensure that all switch interconnects are configured as trunks to allow VTP information to be transferred.

D VTP allows switches to advertise VLAN information between other members of the same VTP domain. VTP allows a consistent view of the switched network across all switches. There are several reasons why the VLAN information can fail to be exchanged. Verify these items if switches that run VTP fail to exchange VLAN information: VTP information only passes through a trunk port. Make sure that all ports that interconnect switches are configured as trunks and are actually trunking. Make sure that if EtherChannels are created between two switches, only Layer 2 EtherChannels propagate VLAN information. Make sure that the VLANs are active in all the devices. One of the switches must be the VTP server in a VTP domain. All VLAN changes must be done on this switch in order to have them propagated to the VTP clients. The VTP domain name must match and it is case sensitive. CISCO and cisco are two different domain names. Make sure that no password is set between the server and client. If any password is set, make sure that the password is the same on both sides.

Which VTP mode is needed to configure an extended VLAN, when a switch is configured to use VTP versions 1 or 2? A. transparent B. client C. server D. Extended VLANs are only supported in version 3 and not in versions 1 or 2.

D VTP version 1 and version 2 support VLANs 1 to 1000 only. Extended-range VLANs are supported only in VTP version 3. If converting from VTP version 3 to VTP version 2, VLANs in the range 1006 to 4094 are removed from VTP control.

Interface FastEthernet0/1 is configured as a trunk interface that allows all VLANs. This command is configured globally: monitor session 2 filter vlan 1 - 8, 39, 52 What is the result of the implemented command? A. All VLAN traffic is sent to the SPAN destination interface. B. Traffic from VLAN 4 is not sent to the SPAN destination interface. C. Filtering a trunked SPAN port effectively disables SPAN operations for all VLANs. D. The trunk's native VLAN must be changed to something other than VLAN 1. E. Traffic from VLANs 1 to 8, 39, and 52 is replicated to the SPAN destination port.

E The "monitor session filter" command is used to specify which VLANS are to be port mirrored using SPAN. This example shows how to monitor VLANs 1 through 5 and VLAN 9 when the SPAN source is a trunk interface: Switch(config)# monitor session 2 filter vlan 1 - 5 , 9

Refer to the exhibit. How many bytes are added to each frame as a result of the configuration? Switch(config)#int fastEthernet 0/1 Switch(config-if)#switchport mode trunk Switch(config-if)#switchport trunk encapsulation dot1q A. 4-bytes except the native VLAN B. 8-bytes except the native VLAN C. 4-bytes including native VLAN D. 8-bytes including native VLAN

In 802.1Q trunking, all VLAN packets are tagged on the trunk link, except the native VLAN. A VLAN tag adds 4 bytes to the frame. Two bytes are used for the tag protocol identifier (TPID), the other two bytes for tag control information (TCI).

What are the different modes for LACP?

active and passive

A manager tells the network engineer to permit only certain VLANs across a specific trunk interface. Which option can be configured to accomplish this? A. allowed VLAN list B. VTP pruning C. VACL D. L2P tunneling

allowed VLAN list When a trunk link is established, all of the configured VLANs are allowed to send and receive traffic across the link. VLANs 1 through 1005 are allowed on each trunk by default. However, VLAN traffic can be removed from the allowed list. This keeps traffic from the VLANs from passing over the trunk link. Note: The allowed VLAN list on both the ends of the trunk link should be the same. For Integrated Cisco IOS Software based switches, perform these steps: 1. To restrict the traffic that a trunk carries, issue the switchport trunk vlan-list interface configuration command. This removes specific VLANs from the allowed list.

SWITCH

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