- Eigrp Redistribute Prefix-list
- Eigrp Route Filtering Prefix List
- Eigrp Distribute-list Prefix
- Eigrp Filter Prefix List
- Cisco Eigrp Distribute List Prefix
Note!
You want restrict which routes EIGRP propagates through the network. You can filter the routes that EIGRP receives on a particular interface (or subinterface) using the distribute-list in command as follows. Router2#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router2(config)#access-list 34 deny 192.168.30.0 Router2(config)#access-list 34. R1(config)# ip prefix-list PRE01 permit 172.16.1.0/24 R1(config)# ip prefix-list PRE01 permit 172.16.2.0/24 R1(config)# router eigrp 1 R1(config-router)# distribute-list prefix PRE01 out GigabitEthernet0/0. Let’s start by creating a prefix-list that blocks our loopback and permits everything else. Ip prefix-list BLOCKR4LOOP deny 150.1.4.4/32 ip prefix-list BLOCKR4LOOP permit 0.0.0.0/0 le 32 router eigrp 100 distribute-list prefix BLOCKR4LOOP out Gi1.45.
Use the basic EIGRP configuration (Lab 45 Task 1) in the labs 45-53.
EIGRP filtering can use:
- Standard ACL.
- Extended ACL.
- Prefix-List.
- Route-Map.
- Administrative Distance.
- Passive-Interface.
- Offset-List.
- Stub Routing.
- Selective Stub Routing (stub routing with leak map).
Pic. 1 - Topology Diagram.
Icons designed by: Andrzej Szoblik - http://www.newo.plTask 1
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_IN seq 10 permit 0.0.0.0/0 le 32
Eigrp Redistribute Prefix-list
!
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
!
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
!
Eigrp Route Filtering Prefix List
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
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
In certain situations an engineer may need to manipulate EIGRP metrics, and one method is to use Offset Lists to increase both the AD (Advertised Distance) and FD (Feasible Distance) of a route by a certain value – the offset.
Offset List configurations define the following:
- route(s) that we want to amend the metric for (matching an ACL)
- direction of the updates being sent or received
- interface on which updates are sent or received
- offset integer value
Network diagram:
Objective One:
when router WEST advertises prefix 10.1.1.0 out of interface Serial0/0, it should add 100 to the metric
Lets first check the FD and AD values that HQ has in its topology table for prefix 10.1.1.0/24:
![Eigrp Prefix List Eigrp Prefix List](/uploads/1/1/8/4/118484827/405890782.png)
Next, we’ll configure the offset list on router WEST:
If we check the FD and AD values on the HQ router again, we’ll see they have both increased by 100:
Objective Two:
when HQ router receives an advertisement for prefix 10.1.2.0 in via interface Serial0/0, it should add 100 to the metric
Lets first check the FD and AD values that HQ has in its topology table for prefix 10.1.2.0/24:
Next, we’ll configure the offset list on router HQ:
If we check the FD and AD values on the HQ router again, we’ll see they have both increased by 100:
Eigrp Distribute-list Prefix
I hope this has been a useful explanation. Thanks for reading, and good luck with your CCNP studies!
Eigrp Filter Prefix List
Rich
Cisco Eigrp Distribute List Prefix
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