Regarding Ip route

[ncnaveen_arasu]

Hi,

Please let me know the meaning of the below sh ip route output.

sh ip route 10.161.5.110

Routing entry for 10.161.5.108/30

  Known via "connected", distance 0, metric 0 (connected, via interface)

  Redistributing via bgp 4758

  Advertised by bgp 4758

  Routing Descriptor Blocks:

  * directly connected, via GigabitEthernet5/1/9.3

      Route metric is 0, traffic share count is 1

We were advertising 10.161.5.108/30 subnet in OSPF but not in BGP. We are runnning MP-BGP for VRF traffic. so what command will cause the route to redistribute in BGP.

Under VRF config we have done the following

address-family ipv4 vrf DAE

redistribute connected

redistribute static

no synchronization

exit-address-family

So how the plain traffic will learn by BGP.

Thanks & Regards,

Naveen

[Rakhmadian Purnama]

Hi Naveen,

Does 10.161.5.108/30 is attached on one of your router interface ?

I guess, because this is directly connected and in your bgp address-family you do redistribute connected that's why its advertised by BGP.

[ncnaveen_arasu]

Hi,

Thanks for the reply and it's directly conected.

[dslice]

Is there an actual problem you're seeing or are you just curious about the wording? This output you're seeing is based on the flags set on the routes in the table and aren't an indication of actual redistribution. If there is a problem seen as well, can you describe it?

Sent from Cisco Technical Support iPad App

[ncnaveen_arasu]

Hi,

Donald it's just an Curiosity for learning. Because under address family if we redistribute it will redistribute the connected routes to that perticulat VRF routing table or in to global routing table.

Beacuse we can see the connected routes in Global table and in VRF table only VRF enabled interface networks were advertised.

Please clarify how learning of routes happened in MP-BGP or BGP when we advertised in IGP protocol.

Thanks & Regards,

Naveen

[dslice]

I'm not sure I understand the question, but I'll take a shot at it.  If I miss the mark, please clarify the question.

Simply, the connected routes are held in different tables for the different VRFs and when the IGP wants to look through them for ownership (in the event of being covered by a network statement) or to redistribute them (if not covered by network statement but covered by some type of redistribution, whether redist conn or redist ospf/etc.) the function call used only looks in the table associated with the VRF the command falls under (or global if no VRF is used.) 

There are a few exceptions having to do with route import/export, but the general case for IGPs is described above.

Does this answer the question?