IS-IS Redistribution

Lessons Discussion
6

Hello Zaman,

If you lab up something like this, first try the basic redistribution commands without route-maps or tags (maybe you did).

I labbed up redistribution between IS-IS processes on IOSv (Cisco VIRL) but whatever I tried, it was impossible to redistribute routes from one process into another. Maybe it’s related to Cisco IOS or the version that I used. The commands are accepted but it doesn’t redistribute anything.

On IOS XR, it works. Here’s a working configuration for three routers connected like this:

R1-R2-R3

hostname R1
!
interface GigabitEthernet0/0/0/0
 ipv4 address 192.168.12.1 255.255.255.0
!
router isis AREA12
 is-type level-2-only
 net 49.0012.0000.0000.0001.00
 log adjacency changes
 interface GigabitEthernet0/0/0/0
  address-family ipv4 unicast
  !
end
hostname R2
!
interface GigabitEthernet0/0/0/0
 ipv4 address 192.168.12.2 255.255.255.0
!
interface GigabitEthernet0/0/0/1
 ipv4 address 192.168.23.2 255.255.255.0
!
router isis AREA12
 is-type level-2-only
 net 49.0012.0000.0000.0002.00
 log adjacency changes
 address-family ipv4 unicast
  redistribute isis AREA23 metric 10
 !
 interface GigabitEthernet0/0/0/0
  address-family ipv4 unicast
!
router isis AREA23
 is-type level-2-only
 net 49.0023.0000.0000.0002.00
 log adjacency changes
 interface GigabitEthernet0/0/0/1
  address-family ipv4 unicast
!
end
hostname R3
interface Loopback0
 ipv4 address 3.3.3.3 255.255.255.255
!
interface GigabitEthernet0/0/0/0
 ipv4 address 192.168.23.3 255.255.255.0
!
router isis AREA23
 is-type level-2-only
 net 49.0023.0000.0000.003.00
 log adjacency changes
 interface Loopback0
  address-family ipv4 unicast
 !
 interface GigabitEthernet0/0/0/0
  address-family ipv4 unicast
  !
end

This redistributes the 3.3.3.3/32 and 192.168.23.0/24 prefixes from one process into another on R2.

RP/0/0/CPU0:R1#show ip route isis
Fri Mar  1 09:22:17.082 UTC

i L2 3.3.3.3/32 [115/20] via 192.168.12.2, 00:04:41, GigabitEthernet0/0/0/0
i L2 192.168.23.0/24 [115/20] via 192.168.12.2, 00:04:41, GigabitEthernet0/0/0/0

Hope this helps. You can add the route-maps / tags to this if needed.

Rene