Traffic Failover

[kishorenath.ram]

Hello

Have 2 ASR router (R1 and R2) each peering (eBGP) with upstream Provider. Both the ASR receives full table from upstream provider except the default.  Sample DIAGRAM attached

Whenever we lose one the Transit circuit, we don’t see proper failover and the fix is to manually shut down the ports facing the downstream on the respective ASR.  Suspecting traffic black hole.

ASRs advertises default to the downstream routers and accepts customer prefix.

 Here is the BGP config on the ASR facing downstream routers. (Default Originate is used)

neighbor x.x.x.x

address-family ipv4 unicast

route-reflector-client

  default-originate

  next-hop-self

  soft-reconfiguration inbound always

route-policy IPv4_default_only out

So the fix is to ask the provider to send default route as well? ANY SUGGESTIONS?

Here is the output from ASR facing internet

RP/0/RSP0/CPU0:ASR9K-2#show bgp 0.0.0.0

Thu Sep 18 21:52:40.099 ADT

% Network not in table

Output from the downstream router:

3400-1#show ip route 0.0.0.0

Routing entry for 0.0.0.0/0, supernet

  Known via "bgp ", distance 200, metric 0, candidate default path, type internal

[kishorenath.ram]

Attached Diagram

[Akash Agrawal]

Taking default route from ISP is good idea. Basically in current design, you are attracting traffic to ASR router even when ASR does not have any route from ISP to reach internet and ofcourse all traffic will be blackholed.

Regards,

Akash