Maipu Administration Guide

Configure IRMP Route Filtering

Network Requirements

The IRMP operated between Device1 and Device2 for routing interaction.
Device1 learns two routing 2.0.0.0/24 and 3.0.0.0/24 advertised by Device2 and Device1 only reserves the routing information of 2.0.0.0/24.

Network Topology

Networking of the IRMP route filtering

Figure 11–4 Networking of the IRMP route filtering

Configuration Steps

Step 1: Configure the IP address of the interfaces. (Omitted)

Step 2: Configure the IRMP.

#Configure Device1.

Device1#configure terminal
Device1(config)#router irmp 100
Device1(config-irmp)#network 1.0.0.0 0.0.0.255
Device1(config-irmp)#exit

#Configure Device2.

Device2#configure terminal
Device2(config)#router irmp 100
Device2(config-irmp)#network 1.0.0.0 0.0.0.255
Device2(config-irmp)#network 2.0.0.0 0.0.0.255
Device2(config-irmp)#network 3.0.0.0 0.0.0.255
Device2(config-irmp)#exit

#View the IRMP neighbor inofrmation of Device1.

Device1#show ip irmp neighbor  
IP-IRMP neighbors for process 100 Total neighbor 1 
Address   Interface          Hold(s) Uptime   SeqNum   Srtt(ms) Rto(s) 
1.0.0.2   gigabitethernet0   11      00:05:00 3        0        2

It can be viewed that the IRMP neighbor is successfully established between Device1 and Device2.

#View the routing table of Device1.

Device1#show ip irmp topology  
IP-IRMP Topology Table for process 100 
Codes: P - Passive, A - Active, H - Holddown, D - Hidden 
        > - FIB route, * - FIB successor 
 
P >1.0.0.0/24, 1 successors, FD is 2816 
        *via Connected (2816/0), gigabitethernet0
P >2.0.0.0/24, 1 successors, FD is 3072 
        *via 1.0.0.2 (3072/2816), gigabitethernet0
P >3.0.0.0/24, 1 successors, FD is 3072 
        *via 1.0.0.2 (3072/2816), gigabitethernet0 
 
Device1#show ip route 
Codes: C - connected, S - static, R - RIP, O - OSPF, OE-OSPF External, M - Management 
       D - Redirect, E - IRMP, EX - IRMP external, o - SNSP, B - BGP, i-ISIS  
 
Gateway of last resort is not set 
 
C 1.0.0.0/24 is directly connected, 00:11:29, gigabitethernet0 
E 2.0.0.0/24 [90/3072] via 1.0.0.2, 00:07:43, gigabitethernet0
E 3.0.0.0/24 [90/3072] via 1.0.0.2, 00:07:40, gigabitethernet0
C 127.0.0.0/8 is directly connected, 00:19:50, lo0

Device1 learns the routing 2.0.0.0/24 and 3.0.0.0/24.

Step 3: Configure the route filtering.

#Configure the ACL rule to only permit the routing 2.0.0.0/24 on Device1 and configure the inbound filtering list to coordinate with the ACL in the IRMP.

Device1(config)#ip access-list standard 1
Device1(config-std-nacl)#permit 2.0.0.0 0.0.0.255
Device1(config-std-nacl)#exit
Device1(config)#router irmp 100
Device1(config-irmp)#distribute-list 1 in
Device1(config-irmp)#exit

When configuring the route filtering, the prefix list and ACL can establish the matching rule. The difference lies in that the prefix list can accurately match the route mask, but the ACL cannot match the route mask.

Step 4: Check the result.

#View the topology table and routing table of Device1.

Device1#show ip irmp topology  
IP-IRMP Topology Table for process 100 
Codes: P - Passive, A - Active, H - Holddown, D - Hidden 
        > - FIB route, * - FIB successor 
 
P >1.0.0.0/24, 1 successors, FD is 2816 
        *via Connected (2816/0), gigabitethernet0
P >2.0.0.0/24, 1 successors, FD is 3072 
        *via 1.0.0.2 (3072/2816), gigabitethernet0 
 
Device1#show ip route 
Codes: C - connected, S - static, R - RIP, O - OSPF, OE-OSPF External, M - Management 
       D - Redirect, E - IRMP, EX - IRMP external, o - SNSP, B - BGP, i-ISIS  
 
Gateway of last resort is not set 
 
C 1.0.0.0/24 is directly connected, 00:22:33, gigabitethernet0 
E 2.0.0.0/24 [90/3072] via 1.0.0.2, 00:04:18, gigabitethernet0
C 127.0.0.0/8 is directly connected, 00:30:55, lo0

Device1 only learns the routing 2.0.0.0/24, but the routing 3.0.0.0/24 is successfully filtered.

Configuring the distribute-list command may cause the IRMP neighbor to be reestablished.