EIGRP-1

Question 1

What is EIGRP?

Answer 1

• (EIGRP) is a distance vector routing protocol which
  uses Diffused Update Algorithm (DUAL) to calculate the shortest path.
• EIGRP supports:
• classless routing
• route summarization
• incremental updates
• load balancing.

Question 2

What are the requirements for neighborship in EIGRP?

Answer 2

The following fields in a hello packet must match for routers to become neighbors:

1. Autonomous System number.
2. K-values.
3. Authentication.
4. Routers must be reachable.

Question 3

What are the metrics (K-Values) of the EIGRP protocol & its default values?

Answer 3

By default, EIGRP only uses Bandwidth (K1) and Delay (K3) to calculate metrics.

1. Bandwidth (K1=1)
2. Load (K2=0)
3. Delay (K3=1)
4. Reliability (K4=0)
5. MTU (K5=0)

Question 4

What are the different packet types used by EIGRP?

Answer 4

EIGRP Neighborhood Packet Types:

• Hello: Forms Relationship, sends hello messages to Multicast Address 224.0.0.10
• Update: Sends Updates and exchange routing tables.
• Query: Asks about routes. EIGRP will send queries if the network goes down.
• Reply: Response to a query
• Ack: Acknowledges the update, query, and reply messages

Question 5

Explain Unequal Cost Load Balancing in EIGRP.

Answer 5

By default, EIGRP will automatically load-balance across equal-metric routes. EIGRP also supports load balancing across routes with an unequal metric.

Router(config)# router eigrp 100
Router(config-router)# variance 2