Redistributing BGP into ISIS

[vasquezwilmer]

I have issue Reditributing BGP into ISIS network. I have Router R1 running ISIS Level-2 with a neighborn router R2 ISIS L1-L2. Router R1 has a peering BGP with another router, so I want to redistribute network that receives from peering BGP and anounce to its neighbour ISIS.

Here are go setting, all seems to be ok, but withen I check into R2 network 172.16.40.0 it gets "% Subnet not in table"

R1 ISIS
R1#sh isis neighbors
R2 L2   Gi9/3       172.30.100.98   UP    24       R1.09  

router isis
 net 49.0001.0000.0000.0024.00
 is-type level-2-only
 redistribute connected
 redistribute bgp 11562 route-map Metricas level-1-2

route-map Metricas permit 10
 match ip address 20

access-list 20 permit 172.16.40.0 0.0.0.255

R1#show ip bgp neighbors 172.16.40.38 received-routes
   Network          Next Hop            Metric LocPrf Weight Path
* i172.16.40.0/24 172.16.40.38             0    100      0 i

Command  "redistribute bgp 11562 route-map Metricas level-1-2" I tried with "redistribute bgp 11562 route-map Metricas level-2"  too, but didnt work. Please, help me

[ghostinthenet]

The prefix you're trying to redistribute into IS-IS is coming from an iBGP peering. By default, the BGP process will not redistribute iBGP into an IGP because this scenario can frequently create routing loops. If you really want to do this and you're sure your routing setup is stable, you can override this behaviour by adding the "bgp redistribute-internal" configuration command under your "router bgp" process.

Make sure you issue a "clear bgp ipv4 unicast *" to clear the BGP table once you've made the configuration change.

[vasquezwilmer]

Thank you for your prompt reply. Unfortunately my IOS (c7600rsp72043_rp-ADVENTERPRISEK9-M) does not support command "bgp redistribute-internal". What can I do? I have Switch Catlyst running ISIS and reditributing BGP without any problem, but is no working thru R1 (Cisco 7609)

[ghostinthenet]

The first option that comes to mind to make the BGP relationship between your router and your switch an eBGP one. You can do this by configuring either your router or switch to use a private AS number (64512-65535) and overcome the iBGP limitation that way, but don't want to recommend anything specific without knowing something more about your routing topology.

[ghostinthenet]

What specific software version are you running on that 7600? According to the Cisco web site, the "ip bgp redistribute-internal" command was introduced in software release 12.2(33)SRA. If you're running something older than that, an upgrade may get you what you need.

[vasquezwilmer]

Hello, I have Cisco Route 7600 with IOS 15.3, command is no supported. I just checked thru Catlayst 4500 IOS 12.2, command is supported. I think that Cisco Series 7600 does not support this feature. Really do not what to do.

[ghostinthenet · Accepted solution]

Interestingly, the command is available on a Catalyst 6500 (with the same supervisor as your 7600) running 12.2(33)SXJ6.

Things are a bit different with 15.3. Have you tried issuing the command under "address-family ipv4 unicast" under the "router bgp" process?

[vasquezwilmer]

Hello Jody, I setup under address-family ipv4 and it works properly. I see routes distributing as I expected. Thank you for your help. Cisco Router 7600 doesnt redistribute internal by default.

[ghostinthenet]

Glad to hear it's working!