[c-nsp] BGP and OSPF - redesign

chris at lavin-llc.com chris at lavin-llc.com
Mon May 11 10:09:05 EDT 2009

Along the lines of the recent discussions about eBGP, iBGP and OSPF intertwined routing, I have a redesign to deal with. An enterprise solution that 
currently runs eBGP, iBGP and OSPF with the iBGP and OSPF fully mixed. By that I mean there lacks a policy of seperating the two. Rather than having 
OSPF carry only the required /32s for the purpose of building the full iBGP mesh, OSPF and BGP are contributing to the forwarding tables for all 
traffic. This is causing some odd and unpredictable behavior for route announcements and path selection.

The problem I'm struggling with is how to transition the routes out of OSPF so that iBGP is used to carry the traffic, thus reducing OSPF based routes 
to only be responsible for building the full iBGP mesh. Most of the appropriate goodies are in place, like locked in router-id's and no synch. But the 
jenga-like configurations of redistribution and network statements make for a mind bending exercise for trying to migrate to the ISP Essentials formula.


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