[c-nsp] Current BGP BCP for anchoring and announcing local prefixes

[Asbjorn Hojmark - Lists]

On Mon, 15 Mar 2010 17:01:07 -0400, you wrote:

>> router bgp <asnr>
>>  address-family ipv4
>>   aggregate-address A.A.A.A M.M.M.M attribute-map BGP-LOCAL
>> 
>> route-map BGP-LOCAL permit 10
>>  set metric 10
>>  set local-preference 1000
>>  set origin igp
>>  set community <whatever>

> Indeed.  That not withstanding, my problem with relying on aggregate-
> address is that the prefix isn't announced unless it, or a candidate
> prefix exists in the BGP table.

True, but in my opinion, that's typically not extremely important: If
there is no component route, the rest of the world has little use of
the aggregate. Also, if the address space is actually in use, there
should always be a component route.


But anyway, if you want to be nice and stable, and the route to never
go away, instead use a static route to null0, and then redistribute
into BGP with a route map.

ip route A.A.A.A M.M.M.M null0

ip access-list standard STATIC-TO-BGP
 permit ip A.A.A.A W.W.W.W

route-map STATIC-TO-BGP permit 10
 match ip address STATIC-TO-BGP
 set metric 10
 set local-preference 1000
 set origin igp
 set community <whatever>

router bgp <asnr>
 address-family ipv4
  redistribute static route-map STATIC-TO-BGP

-A