24 - Implementing EIGRP for IPv6

Question 1

What troubleshooting steps should you take when a router has a suboptimal path to a destination?

Answer 1

1) check neighbor relationships all along the optimal path
2) check interface bandwidth and delay settings. Give special attn to lowest bandwidth along the path since EIGRP will use that to calculate metric.

Question 2

What ‘show’ command will display passive interfaces?

Answer 2

show ipv6 protocols

Question 3

What 3 ‘show’ commands can be used to see EIGRP topology?

Answer 3

• show ipv6 eigrp topology
• show ipv6 eigrp topology (subnet/prefix)
• show ipv6 eigrp topology | sec (subnet/prefix)

Question 4

What will happen if bandwidth or delay settings are changed on an interface?

Answer 4

It will change those values for BOTH ipv4 AND ipv6

Question 5

What 5 values must match before two EIGRP routers become neighbors?

Answer 5

• interfaces must be up/up
• ACLs must not filter EIGRP traffic
• must pass authentication if enabled
• ASNs must be the same
• K values must match

Question 6

What command changes the Hello timer?

Answer 6

(interface cmd) ipv6 hello-interval eigrp (asn) (value). Ex. Ipv6 hello-interval eigrp 2 10

Question 7

What 4 ‘show’ commands can be used to see EIGRP routes?

Answer 7

• show ipv6 route
• show ipv6 route eigrp
• show ipv6 route (subnet/prefix)
• show ipv6 route | sec (subnet/prefix)

Question 8

What troubleshooting steps should you take when a router is missing a route?

Answer 8

1. Check directly connected interface to missing network to make sure EIGRP is enabled correctly
2. Check to make sure neighbor relationships exist all along the path

Question 9

How do you explicitly set the router ID for EIGRP for IPv6

Answer 9

(router cmd) eigrp router-id 2

Question 10

What 3 ‘show’ commands can be used to see EIGRP neighbors?

Answer 10

• show ipv6 eigrp neighbors
• show ipv6 eigrp neighbors gig0/0
• show ipv6 protocols

Question 11

What command changes the Hold timer?

Answer 11

(interface cmd) ipv6 hold-time eigrp (asn) (value). Ex. Ipv6 hold-time eigrp 2 10

Question 12

What is the feasibility condition?

Answer 12

the metric reported by the neighboring router must be lower (better) than that of the local router

Question 13

How do you enable and disable EIGRP without changing the EIGRP configuration?

Answer 13

(router cmd) ‘shutdown’ and (router cmd) ‘no shutdown’

Question 14

What 2 things does EIGRP attempt to do when enabled on an interface?

Answer 14

• discover and become neighbors
• advertise that interface’s network

Question 15

Will two routers be prevented from becoming neighbors if their router IDs are the same?

Answer 15

No

Question 16

What command enables EIGRP for IPv6 on an interface?

Answer 16

(interface cmd) ipv6 eigrp (asn)

Question 17

What 4 ‘show’ commands can be used to see EIGRP-enabled interfaces?

Answer 17

• show ipv6 eigrp interfaces
• show ipv6 eigrp interfaces detail
• show ipv6 eigrp interfaces gig0/0
• show ipv6 protocols

Question 18

Do IPv6 EIGRP neighbors need to be on the same subnet?

Answer 18

No

Question 19

Do timers need to match on two routers in order for them to become neighbors?

Answer 19

No

Question 20

When looking at a neighbor table how are neighboring routers identified?

Answer 20

By their Link-Local address

Question 21

As a minimum what are the two commands needed to bring up EIGRP for IPv6?

Answer 21

• Global cmd) ipv6 router 2
• (interface cmd) ipv6 eigrp 2