Ok, time for the next routing protocol – RIP. Why would you use IOS XR for RIP? Well, if you have a CE device that only has a few networks, RIP is a perfect protocol. Keep in mind that IOS XR is code built for a Service Provider network, so PE-CE relationships are what these routers are about. Another quick note on these labs, I do not show the configuraiton of the other device (R2) as it is just a mirrored config.
Plus – it is just good to know different options.
RP/0/7/CPU0:R1#conf t
Thu Mar 29 20:37:44.801 UTC
RP/0/7/CPU0:R1(config)#router rip
RP/0/7/CPU0:R1(config-rip)#int l0
RP/0/7/CPU0:R1(config-rip-if)#int g0/3/0/2
RP/0/7/CPU0:R1(config-rip-if)#^Z
Uncommitted changes found, commit them before exiting(yes/no/cancel)? [cancel]:yes

Notice I did not do a COMMIT, but since the router knows I was making changes it asked me.
Let’s check our IP protocols:
RP/0/7/CPU0:R1#sh ip proto
Thu Mar 29 20:39:20.919 UTC
Routing Protocol RIP
1 VRFs (including default) configured, 1 active
6 routes, 3 paths have been allocated
Current OOM state is “Normal”
UDP socket descriptor is 42
VRF Active If-config If-active Routes Paths Updates
default Active 2 2 6 3 30s


Now lets look at the RIP process:
RP/0/7/CPU0:R1#sh rip
Thu Mar 29 20:39:24.892 UTC
RIP config:
Active: Yes
Added to socket: Yes
Out-of-memory state: Normal
Version: 2
Default metric: Not set
Maximum paths: 4
Auto summarize: No
Broadcast for V2: No
Packet source validation: Yes
NSF: Disabled
Timers: Update: 30 seconds (0 seconds until next update)
Invalid: 180 seconds
Holddown: 180 seconds
Flush: 240 seconds
RP/0/7/CPU0:R1#
Now here is something interesting, the RIP version is 2, yet I did not specify it in the config. This is because IOS XR code only supports v2.
RP/0/7/CPU0:R1(config)#router rip
RP/0/7/CPU0:R1(config-rip)#ver?
^
% Invalid input detected at ‘^’ marker.
Now, let’s look at the routing table using the proper command:
RP/0/7/CPU0:R1#sh route ipv4
Thu Mar 29 20:40:08.877 UTC
Codes: C – connected, S – static, R – RIP, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2, E – EGP
i – ISIS, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, su – IS-IS summary null, * – candidate default
U – per-user static route, o – ODR, L – local, G – DAGR
A – access/subscriber, (!) – FRR Backup path
Gateway of last resort is not set
L 1.1.1.1/32 is directly connected, 01:14:39, Loopback0
R 2.2.2.2/32 [120/1] via 150.1.12.2, 00:01:25, GigabitEthernet0/3/0/2
C 150.1.12.0/24 is directly connected, 02:01:22, GigabitEthernet0/3/0/2
L 150.1.12.1/32 is directly connected, 02:01:22, GigabitEthernet0/3/0/2
RP/0/7/CPU0:R1#
As you can see, we have a RIP route to R2 L0 2.2.2.2/32 interface. Time for a PING!
RP/0/7/CPU0:R1#ping 2.2.2.2 so l0
Thu Mar 29 20:40:15.606 UTC
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 2/3/4 ms
RP/0/7/CPU0:R1#
And like that RIP is configured.