Passive Interfaces for EIGRP Updates
The objective of this lab exercise is for you to learn and understand how to prevent EIGRP from sending unnecessary updates by using passive interfaces.
Preventing unnecessary EIGRP updates using passive interfaces is a fundamental skill. By default, EIGRP sends updates via Multicast on all interfaces for which EIGRP has been enabled. This means that EIGRP adjacencies will form on all interfaces for which EIGRP has been enabled. In some cases, this may not be desirable and should be prevented. As a Cisco engineer, as well as in the Cisco CCNA exam, you will be expected to know how to prevent EIGRP from sending unnecessary updates.
This lab is suitable for CCNA certification exam preparation
This lab has a difficulty rating of 7/10
When you are ready for your certification exam, you should complete this lab in no more than 10 minutes
Please use the following topology to complete this lab exercise:
Configure the hostnames on routers R1, R2, and Sw1 as illustrated in the topology.
Configure VLAN 10 named EIGRP_10 and VLAN 20 named EIGRP_20 on Sw1. Next, configure Sw1 F0/2 and F0/3 as trunks. These should be connected to R1 and R2 F0/0 interfaces, respectively.
Configure subinterfaces Fa0/0.10 and F0/0.20 on R1 and R2. Subinterface Fa0/0.10 on either router should be associated with VLAN 10 and subinterface Fa0/0.20 on either router should be associated with VLAN 20. Configure IP addresses on both the subinterfaces as illustrated in the topology.
Ping between R1 and R2 on subinterface Fa0/0.10 and Fa0/0.20 to verify IP connectivity.
Enable EIGRP using Autonomous System 10 on R1 and R2 F0/0.10 and F0/0.20 subinterfaces and verify that you have two EIGRP neighbor adjacencies on R1 and R2, one through the F0/0.10 and the other through the Fa0/0.20 subinterface. On either R1 or R2, verify that you have two EIGRP adjacencies to your peer router.
Prevent EIGRP from forming an adjacency via Fa0/0.20 on R1 and R2. Verify that you now only have one EIGRP neighbor adjacency on R1 and R2, only through each F0/0.10 subinterface.