BGP Backdoor Routes

jpl861 · ‎04-29-2008

Hi,

I understand the concept of BGP's network backdoor command. I would just like to know if it will also work when the BGP received route is an iBGP. iBGP's Administrative Distance in our routing domain was set to 20, eBGP 20, and locally injected BGP is also set to 20. Thanks.

-John

Harold Ritter · ‎04-30-2008

John,

The backdoor concept is not necessary if the route is received via iBGP as you can use the local-preference to make the iBGP route preferred over the eBGP.

The admin distance doesn't come into play in this context as the decision is taken by the BGP best path selection process. Admin distance would come into play if you had the same route learnt via two different sources.

Regards,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
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