Wednesday, March 16, 2011

Lab 47 - EIGRP Filtering with Prefix-List

Prerequisites: CCNP level skills.

Note!
Use the basic EIGRP configuration (Lab 45 Task 1) in the labs 45-53.

EIGRP filtering can use:
  1. Standard ACL.
  2. Extended ACL.
  3. Prefix-List.
  4. Route-Map.
  5. Administrative Distance.
  6. Passive-Interface.
  7. Offset-List.
  8. Stub Routing.
  9. Selective Stub Routing (stub routing with leak map).
Topology


Pic. 1 - Topology Diagram.
Icons designed by: Andrzej Szoblik - http://www.newo.pl

Task 1
Using prefix-list prevent R3 from advertising 172.16.133.0/24. Also make sure it does not learn 172.16.144.0/24.

Lab Solution

Task 1
Using prefix-list prevent R3 from advertising 172.16.133.0/24. Also make sure it does not learn 172.16.144.0/24.


Pic. 2 - R3's Routing Table Before Applying the Filter.

Pic. 3 - R4's Routing Table. 
 R3 Configuration:
!
ip prefix-list EIGRP_IN seq 5 deny 172.16.144.0/24
ip prefix-list EIGRP_IN seq 10 permit 0.0.0.0/0 le 32
!
ip prefix-list EIGRP_OUT seq 5 deny 172.16.133.0/24
ip prefix-list EIGRP_OUT seq 10 permit 0.0.0.0/0 le 32
!
router eigrp 1
 network 10.1.13.3 0.0.0.0
 network 10.1.123.3 0.0.0.0
 network 172.16.103.3 0.0.0.0
 network 172.16.133.3 0.0.0.0
 distribute-list prefix EIGRP_OUT out
 distribute-list prefix EIGRP_IN in
 no auto-summary
!

Pic. 4 - R3's Routing Table After Applying Filter EIGRP_IN.
Pic. 5 - R4's Routing Table After Applying
Filter EIGRP_OUT On R3.