Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Internet routers BGP / OSPF config

Hi all

Can anyone confirm or help me to see how our internet routers are set up

We currently have 2 internet routers both on different ISP's

we receive a default route on both, these routers then connect to some internal routers using OSPF which advertises our PI address range.

1 internet router is active, the other is currently in standby both in and out

I asked the consultant how they are set up for resilience, the reply was         

"the backup internet router just learns the route from the first – if it sees the route in the table it doesn’t advertise it itself out to the internet"

what does thsi mean and how would you think it is set up ?


New Member

Internet routers BGP / OSPF config

Hi Carl,

I think the backup router has an ibgp connection to the active one, has a lower local-preference to its wan link (outbound traffic) and advertises your ip address space with as-path prepending or some communities agreed with the ISP (inbound traffic).

You can check this video for local preference and as-path prepend:

And this for bgp communities:


Pedro Lereno

CreatePlease login to create content