[c-nsp] BGP and OSPF - redesign

David Hughes david at hughes.com.au
Mon May 11 19:37:48 EDT 2009

On 12/05/2009, at 12:09 AM, <chris at lavin-llc.com> <chris at lavin- 
llc.com> wrote:

> 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.

Had a similar problem a few years back.  Pete Templin's comments are  
good.  Our actual process was

* redist connected and static into iBGP at the customer edge
* check all loopbacks and point-to-points were in OSPF
* for each edge box
	- for each connected or static route route
		- check route is visible via BGP at the router reflectors
		- remove from ospf on edge box
		- check route is visible via BGP at the router reflectors :)

Slow and tedious process but a major migration was undertaken without  
an impact.


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