[c-nsp] what's the right way to redistribute certain bgp prefixedinto ospf?

[Oliver Boehmer (oboehmer)]

matthew zeier <mailto:mrz at velvet.org> wrote on Wednesday, December 06,
2006 11:44 AM:

> Oliver Boehmer (oboehmer) wrote:
>>> I have one or two BGP prefixes I need to get into my IGP - what's
>>> the right way to get a specific BGP prefix into OSPF?
>> 
>> redistribute bgp <foo> route-map <bar>
>> 
>> route-map <bar> permit 10
>>  match ip address ...
> 
> So to clarify, something like the following?
> 
> ip prefix-list ams-routes permit 163.245.212.0/22
> 
> route-map ams-prefix permit 10
>   match ip address prefix-list ams-routes
> 
> router ospf 1
>   redistribute bgp 65001 route-map ams-prefix subnets
>   redistribute maximum-prefix 200 80

yep, like this, assuming the prefix is seen as "external" on this
router.. I'd reverse the order and configure the max-prefix before
applying the redistribute cmd. I'm being extra-cautious with this and
would even try this in the lab first ;-))

> (Basically I have one site announcing the supernet /20 and another
> site with a different ASN announcing the /22.  My BGP speaking
> routers have no problem with it but my OSPF-only routers are only
> seeing the nailed up /20.  So I need some way to get the remote /22
> into the IGP here.) 

well, have you evaluated other options, like not announcing the /20 into
your IGP and have the OSPF-only nodes follow a default to the next BGP
core router? 

	oli