CCNP Route FAQ: EIGRP Overview and Neighbor Relationships
Q1. A router has been configured with the commands router eigrp 9 and network 172.16.1.0 0.0.0.255. No other EIGRP-related commands have been configured. The answers list the IP addresses that could be assigned to this router’s Fa0/0 interface.
Which answers list an IP address/prefix length that would cause the router to enable EIGRP on Fa0/0?
e. None of the other answers is correct.
Q2. Router R1 has working interfaces S0/0, S0/1, and S0/2, with IP address/prefix combinations of 10.10.10.1/24, 10.10.11.2/24, and 10.10.12.3/22. R1’s configuration includes the commands router eigrp 9 and network 10.0.0.0. The show ip eigrp interfaces command lists S0/0 and S0/1 in the command output, but not S0/2. Which answer gives the reason for the omission? (Choose two answers.)
a. R1 has EIGRP neighbors reachable via S0/0 and S0/1, but not via S0/2, so it is not included.
b. S0/2 may currently be in a state other than up/up.
c. The network 10.0.0.0 command requires the use of mask 255.0.0.0 due to EIGRP being classful by default.
d. S0/2 may be configured as a passive interface.
Q3. Routers R1 and R2 are EIGRP neighbors using their Fa0/0 interfaces, respectively. An engineer adds the ip hello-interval eigrp 9 6 command to R1’s Fa0/0 configuration.
Which of the following is true regarding the results from this change?
a. The show ip eigrp neighbors command on R1 lists the revised Hello timer.
b. The show ip eigrp interfaces command on R1 lists the revised Hello timer.
c. The R1-R2 neighborship fails due to Hello timer mismatch.
d. The show ip eigrp interfaces detail command on R1 lists the revised Hello timer.
Q4. Routers R1 and R2, currently EIGRP neighbors over their Fa0/0 interfaces (respectively), both use EIGRP authentication. Tuesday at 8 p.m. the neighborship fails.
Which of the following would not be useful when investigating whether authentication had anything to do with the failure?
a. debug eigrp packet
b. show key chain
c. show ip eigrp neighbor failure
d. show clock
Q5. Router R1 has been configured with the commands router eigrp 9 and network 172.16.2.0 0.0.0.255, with no other current EIGRP configuration. R1’s (working) Fa0/0 interface has been configured with IP address 172.16.2.2/26. R1 has found three EIGRP neighbors reachable via interface Fa0/0, including the router with IP address 172.16.2.20. When the engineer attempts to add the neighbor 172.16.2.20 fa0/0 command in EIGRP configuration mode, which of the following occurs?
a. Fa0/0 fails.
b. The command is rejected.
c. The existing three neighbors fail.
d. The neighborship with 172.16.2.20 fails and then reestablishes.
e. None of the other answers is correct.
Q6. Which of the following settings could prevent two potential EIGRP neighbors from becoming neighbors? (Choose two answers.)
a. The interface used by one router to connect to the other router is passive in the EIGRP process.
b. Duplicate EIGRP router IDs.
c. Mismatched Hold Timers.
d. IP addresses of 10.1.1.1/24 and 10.2.2.2/24, respectively.
Q7. An engineer has added the following configuration snippet to an implementation planning document. The configuration will be added to Router R1, whose Fa0/0 interface connects to a LAN to which Routers R2 and R3 also connect. R2 and R3 are already EIGRP neighbors with each other. Assuming the snippet shows all commands on R1 related to EIGRP authentication, which answer lists an appropriate comment to be made during the implementation plan peer review?
key chain fred
ip authentication key-chain eigrp 9 fred
a. The configuration is missing one authentication-related configuration command.
b. The configuration is missing two authentication-related configuration commands.
c. Authentication type 9 is not supported; type 5 should be used instead.
d. The key numbers must begin with key 1, so change the key 3 command to key 1.
Q8. A company has a Frame Relay WAN with one central-site router and 100 branch office routers. A partial mesh of PVCs exists: one PVC between the central site and each of the 100 branch routers. Which of the following could be true about the number of EIGRP neighborships?
a. A partial mesh totaling 100: one between the central-site router and each of the 100 branches.
b. A full mesh – (101 * 100) / 2 = 5050–One neighborship between each pair of routers.
c. 101–One between each router (including the central site) and its nearby PE router.
d. None of the answers is correct.