06 - Understanding EIGRP

Question 1

EIGRP multicast address?

Answer 1

224.0.0.10

Question 2

What are the benefits of EIGRP?

Answer 2

• Rapid convergence – using DUAL algorithm
• Load balancing – equal and unequal
• Classless
• Multi-address family support
• Reduced bandwidth use
- Partial updates – doesn’t send full routing table
-Bounded updates – just sends partial updates to routers affected by change
-Uses multicast and unicast as opposed to broadcast

Question 3

EIGRP runs directly above the IP layer as protocol number __.

Answer 3

88

Question 4

What are the EIGRP packet types?

Answer 4

1. Hello – used to discover neighbour
2. Update – used to communicate the routes that a router has used to converge
3. Query – queries other eigrp neighbours for FS when eigrp is recomputing a route in which the router does not have a FS
4. Requests – request packets that are used to get specific information from one or more neighbours
5. Reply – sent as a response to an EIGRP query packet
6. Acknowledge – acknowledges EIGRP updates, queries and replies

Question 5

What is an EIGRP passive route?

Answer 5

The router is not performing re-computation for that route

Question 6

What is an EIGRP active route?

Answer 6

The router is performing re-computation to seek for a new successor when existing successor has become invalid

Question 7

Which parameters should match in order for EIGRP to create a neighbour adjacency?

Answer 7

• AS Number
• K Values
• Common subnet
• Authentication method & password

Question 8

EIGRP doesn’t care that ___ timers between neighbours are mismatched like OSPF.

Answer 8

hello

Question 9

Only ___ and ___ understand what an Autonomous System is.

Answer 9

EIGRP, BGP

Question 10

What are the default EIGRP metrics?

Answer 10

K1 Bandwidth & K3 Delay by default

Question 11

What are the full list of metric K-values?

Answer 11

1. Bandwidth
2. Load
3. Delay
4. Reliability
5. Reliability

Question 12

How do you view K-values?

Answer 12

show ip protocol

Question 13

What is the feasible distance?

Answer 13

A metric for a local router to reach destination network. The sum of advertised distance on a neighbour, and the metric to reach the neighbour

Question 14

What is the advertised distance?

Answer 14

A metric for an EIGRP neighbour to reach a destination network, also known as reported distance.

Question 15

What is a successor?

Answer 15

a route with best metric to destination, placed in the routing table

Question 16

What is a feasible successor?

Answer 16

an alternative backup path to destination

Question 17

Up to _ routes with a metric equal to the minimum metric are installed in routing table.

Answer 17

4

Question 18

The ____ command sets the amount of paths that can be equal load balanced. Cisco routers support upto __. Changing it to _ disables load balancing. If you adjust the ______ value, it must be the same on both sides

Answer 18

maximum-paths, 16, 1, maximum-paths

Question 19

What are the features of unequal cost load balancing?

Answer 19

• Uses metrics to decide which path to use
• Uses the variance command
• Turned off by default
• Performed through paths up to 128 times worse metrics than success route

Question 20

When you use the __ command with the keyword min, the traffic is sent only across the minimum-cost path, even when there are multiple paths in the routing table

Answer 20

traffic-share