[c-nsp] Converting OSPF backbone to iBGP

[Oliver Boehmer (oboehmer)]

Nathan <> wrote on Thursday, October 16, 2008 4:23 PM:

> On Wed, Sep 24, 2008 at 12:01 PM, Phil Mayers
> <p.mayers at imperial.ac.uk> wrote: 
>> You can import from OSPF to BGP, but it has some risks and
>> complexities that are best avoided if at all possible. Much worse is
>> distributing BGP into OSPF - don't do that.
> 
> In case someone even thinks of ever doing that, please note:
> 
> rtr(config)# router ospf 10
> rtr(config-rtr)# redistribute bgp 65000 subnets route-map
> JustATeensyFiftyRoutesOrSo
> 
> certainly does works as advertised (no idea if it consumes a lot of
> CPU to filter out all those routes) . . . but trying to remove that
> using
> 
> rtr(config-rtr)# no redistribute bgp 65000 subnets route-map
> JustATeensyFiftyRoutesOrSo
> 
> results in
> 
>    redistribute bgp 65000 subnets
> 
> and that *hurts*

agree, however this is the only way to remove redistribution options
without removing the actual redistribution. I would advise to always use
"redistribute maximum-prefix" when redistributing BGP into an IGP, just
an addtl. safeguard against this kind of problems.

	oli