Lab 46 - EIGRP Filtering with Extended ACL

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

EIGRP has been configured on all interfaces of all the routers in the topology (pic.1). On R4 configure EIGRP filtering using extended ACL so that R1 is used as the next-hop towards 172.16.103.0/24 and R2 is the next-hop towards 172.16.133.0/24.

Lab Solution

Task 1

EIGRP has been configured on all interfaces of all the routers in the topology (pic.1). On R4 configure EIGRP filtering using extended ACL so that R1 is used as the next-hop towards 172.16.103.0/24 and R2 is the next-hop towards 172.16.133.0/24.

 Pic. 2 - R4's Routing Table Before  Applying the Filter.

R4 Configuration:

!

access-list 100 deny   ip host 10.1.124.1 host 172.16.133.0
access-list 100 deny   ip host 10.1.124.2 host 172.16.103.0
access-list 100 permit ip any any

!

router eigrp 1
 network 10.1.124.4 0.0.0.0
 network 172.16.104.4 0.0.0.0
 network 172.16.144.4 0.0.0.0
 distribute-list 100 in FastEthernet1/0
 no auto-summary

!

Note!
As of writing this post the 'distribute-list' won't take named extended ACL.

Notice!
In an extended ACL, the source IP address is matching on the advertising router, the destination IP address on the prefixes being advertised.

Verification:

Pic. 3 - R4's Routing Table After Apply the Filter.

Pic. 5 - Traceroute from R4.