EIGRP

Question 1

What are the 3 table in EIGRP

Answer 1

Question 2

What IP Protocol does EIGRP use?

Answer 2

88 EIGRP

Reliable Transport Protocol

Question 3

What does a EIGRP Hello Packet contain?

Answer 3

1. Autonomous System # (two separate EIGRP Process will not share routes, you would need to redistribute routes).
2. Hold down timer (does not have to match between router)
3. Authentication
4. Metric Weightings (K Values)

Question 4

What address are EIGRP updates sent to?

Answer 4

224.0.0.10 ro unicast directly to neighbor

Question 5

What best path Algrithum does EIGRP use?

Answer 5

DUAL creats a metric value.

Question 6

What is Split Horizon?

Answer 6

Don’t advertise routes out the link they came in on

Question 7

What is Quary?

Answer 7

To ask adjacent neighbors for a topology update.

Question 8

DUAL Feasibility condition

Answer 8

• Finds loop free backup routes
• AD < FD, Path is loop-free and closer to destination. viable backup

Question 9

Successor?

Answer 9

Best path to a destination (route)

It will be added to the routing table

Question 10

Feasible Distance (FD)

Answer 10

Composite metric of best path (Metric)(Metric you advertise)

The total distance to the destination.

Question 11

Feasible Successor (FS)

Answer 11

Backup Path to a destination

Question 12

Advertised Distance (AD)

Answer 12

Composite metric learned from neighbor (Metric)(Metric you receive)

How far the destination is away for your neighbor.

Question 13

Local Distance (LD)

Answer 13

Composite metric to reach local neighbor

Question 14

ID the Successor and Feasible Successor paths.

Answer 14

Question 15

The EIGRP Metric consist of 4 criteria. What are they

Answer 15

• Bandwidth (default)
• Delay (Default)
• Load
• Reliability

Question 16

Name the 5 different packets that EIGRP uses.

Answer 16

• Hello Used for neighbor discovery
• Update Packets have routing information and are sent to router that requier this it.
• Query When a EIGRP router has lost information about a certain does not have a backup path
• Reply Used to reply to a Query packet
• ACK acknowledge the receipt of update, query, and reply packet

Question 17

Name 6 things that could go wrong when forming a EIGRP neighbor adjacency.

Answer 17

Uncommon subnet: EIGRP neighbors with IP addresses that are not in the same subnet.

K value mismatch: By default bandwidth and delay are enabled for the metric calculation. We can enable load and reliability as well but we have to do it on all EIGRP routers.

AS mismatch: The autonomous system number has to match on both EIGRP routers in order to form a neighbor adjacency.

Layer 2 issues: EIGRP works on layer 3 of the OSI-model. If layer 1 and 2 are not working properly we’ll have issues with forming a neighbor adjacency.

Access-list issues: It’s possible that someone created an access-list that filters out multicast traffic. EIGRP by default uses 224.0.0.10 to communicate with other EIGRP neighbors.

NBMA: Non Broadcast Multi Access networks like frame-relay will not allow broadcast or multicast traffic by default. This can prevent EIGRP from forming EIGRP neighbor adjacencies.

Question 18

What is a Uncommon Subnet Error?

Answer 18

Question 19

What is a K-Value Mismatch Rule?

Answer 19

Question 20

What is the EIGRP AS Mismatch Error?

Answer 20

Question 21

What is the passive interface errror.

Answer 21

Question 22

What security measure could prevent neighbor adjacency from forming?

Answer 22

Question 23

How could a NBMA network effect Neighbor Adjacency?

Answer 23