1. Refer to the exhibit. An administrator attempts to configure EIGRP for IPv6 on a router and receives the error message that is shown. Which command must be issued by the administrator before EIGRP for IPv6 can be configured?
- no shutdown
- eigrp router-id 100.100.100.100
- ipv6 unicast-routing
- ipv6 eigrp 100
- ipv6 cef
Explanation: Before EIGRP for IPv6 can be configured on a router, routing for IPv6 must be configured. This is accomplished by issuing the global configuration command ipv6 unicast-routing.
2. Which destination MAC address is used when a multicast EIGRP packet is encapsulated into an Ethernet frame?
- 01-00-5E-00-00-09
- 01-00-5E-00-00-10
- 01-00-5E-00-00-0A
- 01-00-5E-00-00-0B
Explanation: When an EIGRP multicast packet is encapsulated into an Ethernet frame, the destination MAC address is 01-00-5E-00-00-0A.
3. Which destination address is used for EIGRP query, update, and hello packets?
- FF02::1A
- FF02::1:FF00:111
- FF02::A
- FF02::11
Explanation: When EIGRPv6 is enabled, the routers communicate with each other using the interface IPv6 link-local address as the source, and, depending on the EIGRP packet type, the destination address may be either a unicast link-local address (acknowledgment, reply, and update) or the multicast link-local scoped address FF02::A (hello, query, and update). The address FF02::A is also used to form neighbor adjacencies.
4. Which destination address is used by EIGRP for IPv6 messages?
- the all-EIGRP-routers multicast address
- the IPv6 global unicast address of the neighbor
- the 32-bit router ID of the neighbor
- the unique local IPv6 address of the neighbor
Explanation: EIGRP for IPv6 uses the all-EIGRP-routers link-local multicast address as the destination address for EIGRP messages.
5. Which two statements describe features of EIGRP implemented for IPv4 and IPv6? (Choose two.)
- EIGRP for IPv4 does not require the no shutdown command in router configuration mode.
- EIGRP for IPv6 uses a 32-bit router-id.
- EIGRP for IPv6 does not require the same autonomous system number to be used between two neighboring EIGRP routers.
- EIGRP for IPv6 does not use the passive-interface command within router configuration mode.
- EIGRP for IPv4 is enabled by theip unicast-routing global configuration mode command.
Explanation: With the implementation of EIGRP for IPv6, the autonomous system number must be the same between neighboring routers that form an adjacency. EIGRP for IPv6 uses the passive-interface command within router configuration mode. EIGRP for IPv4 does not require the ip unicast-routing global configuration command to be enabled.
6. How does EIGRP for IPv6 select a router ID if the router ID is not manually configured?
- It uses the highest link-local address that is configured on an active EIGRP for IPv6 interface.
- It is uses the EUI-64 process to automatically generate the router ID based on the highest configured IPv6 address value.
- It uses the highest IPv6 address that is configured on any enabled EIGRP for IPv6 interface.
- It uses the highest IPv4 address that is configured on an operating interface.
Explanation: EIGRP for IPv6 uses the same router ID as EIGRP for IPv4 uses. The 32-bit number can be configured with the router-id command or automatically assigned from the highest IPv4 address on an enabled interface.
7. Which two aspects of the configuration of EIGRP for IPv6 differ from its configuration for IPv4? (Choose two.)
- For IPv6 no router ID is required for the EIGRP routing process to start.
- No network command is needed to enable EIGRP for IPv6.
- IPv6 requires a global unicast address on EIGRP interfaces.
- For IPv6, the autonomous system values on routers in a domain running EIGRP do not have to match.
- EIGRP on IPv6 is configured directly on router interfaces.
Explanation: Some aspects of EIGRP configuration are the same for both IPv4 and IPv6. For instance, a router ID is still required, and autonomous system values on routers in the same domain must match. However, unlike EIGRP for IPv4, EIGRP for IPv6 does not include a network command. Instead, EIGRP is configured directly on interfaces. IPv6 global unicast addresses are not required, although IPv6 link-local addresses are.
8. Which address is used by an IPv6 EIGRP router as the source for hello messages?
- the 32-bit router ID
- the IPv6 global unicast address that is configured on the interface
- the all-EIGRP-routers multicast address
- the interface IPv6 link-local address
Explanation: EIGRP for IPv6 uses the link-local address of the router exit interface as the source address for EIGRP messages, including the hello message.
9. What operational feature is different for EIGRP for IPv6 compared to EIGRP for IPv4?
- DUAL algorithm calculations
- the type of value used for the router ID
- neighbor discovery mechanisms
- the source and destination addresses used within the EIGRP messages
Explanation: Most of the EIGRP operational features are the same for IPv6 as they are for IPv4. Both use the same DUAL algorithm calculations, metric values, neighbor discovery mechanisms, and 32-bit router ID. What is not the same between the protocols are the source and destination addresses used for EIGRP messages.
10. An administrator is troubleshooting a neighbor relationship issue between two routers in an EIGRPv6 network. The administrator suspects that the k values are mismatched. What command can be used to view the k values?
- show ipv6 protocols
- show ipv6 eigrp interfaces detail
- show ipv6 eigrp interfaces
- show key chain
Explanation: The show ipv6 protocols command is used to display the k values. Mismatched k values can prevent EIGRPv6 neighbor relationships from forming.
11. An administrator is troubleshooting a router that has an interface that is not participating in the EIGRPv6 process? The administrator suspects that this might be because of a passive interface. What command can be used to verify this theory?
- show ipv6 eigrp interfaces
- show ipv6 eigrp interfaces detail
- show ipv6 protocols
- show ipv6 route
Explanation: A passive interface in EIGRP suppresses the exchange of hello packets between two routers. This results in the loss of the neighbor relationship. The show ipv6 eigrp interfaces command does not show passive interfaces. However, show ipv6 protocols does.
12. An administrator is troubleshooting authentication between two routers in an EIGRPv6 network. The administrator wants to check to ensure that authentication has been enabled and to verify that the key ID and key string are not mismatched between the two routers. Which two commands can be used to get this information? (Choose two.)
- show ipv6 eigrp interfaces detail
- show ipv6 protocols
- show key chain
- show ipv6 eigrp neighbors
- show ipv6 eigrp interfaces
Explanation: The show ipv6 eigrp interfaces detail command is used to see whether an interface is enabled for EIGRPv6 authentication and the show key chain is used to verify the configuration of the keychain that is being used.
“Do I Know This Already?” Quiz Answers:
1. What address does the EIGRPv6 hello packet use for the destination address?
- MAC address 00:C1:00:5C:00:FF
- MAC address E0:00:00:06:00:AA
- IP address 224.0.0.8
- IP address 224.0.0.10
- IPv6 address FF02::A
- IPv6 address FF02::8
Explanation: EIGRPv6 uses link-local addresses for a majority of communication, but it uses the destination IPv6 address FF02::A for hello, query, and update packets.
2. Enabling EIGRPv6 on an interface with EIGRPv6 classic configuration requires _____.
- the command network prefix/prefix-length under the EIGRP process
- the command network interface-id under the EIGRP process
- the command ipv6 eigrp as-number under the interface
- nothing; EIGRPv6 is enabled on all IPv6 interfaces upon initialization of the EIGRP process
Explanation: EIGRPv6 classic configuration requires identification with the command ipv6 eigrp as-number under the router.
3. Enabling EIGRPv6 on an interface with EIGRPv6 named mode configuration requires _____.
- the command network prefix/prefix-length under the EIGRP process
- the command network interface-id under the EIGRP process
- the command ipv6 eigrp as-number under the interface
- nothing; EIGRPv6 is enabled on all IPv6 interfaces upon initialization of the EIGRP process
Explanation: All EIGRPv6 interfaces become active when the IPv6 address family has been identified under the process.
4. Which EIGRPv6 command is used to verify whether any interfaces have been configured as passive interfaces?
- show ipv6 protocols
- show ipv6 eigrp interfaces detail
- show ipv6 eigrp neighbors detail
- show ipv6 eigrp topology
5. Which EIGRPv6 command enables you to verify whether the local router is a stub router?
- show ipv6 protocols
- show ipv6 eigrp interfaces detail
- show ipv6 eigrp neighbors detail
- show ipv6 eigrp topology
6. Which EIGRPv6 command enables you to verify whether a neighboring router is a stub router?
- show ipv6 protocols
- show ipv6 eigrp interfaces detail
- show ipv6 eigrp neighbors detail
- show ipv6 eigrp topology
7. Which of these commands can you use to verify which interfaces are participating in the named EIGRP IPv4 address family? (Choose two.)
- show ip eigrp interfaces
- show eigrp address-family ipv4 interfaces
- show ipv6 eigrp interfaces
- show eigrp address-family ipv6 interfaces
8. Which of the following must match to form an EIGRPv6 neighborship? (Choose two.)
- The subnet the interfaces belong to
- The autonomous system number
- The passive interfaces
- The K values
9. What must be permitted within an IPv6 ACL for an EIGRPv6 neighbor adjacency to be formed?
- FF02::A
- FF02::10
- The link-local address of the neighboring device
- The global address of the neighboring device