[c-nsp] Filtering OSPF routes from MPBGP to BGP speaker in the same VRF

[Tim.wall07@gmail.com]

Filter bgp routes at both ce's. This will mean that only ospf knows the routes and bgp will no longer see the rib failures



On 26 Feb 2012, at 06:57, Jason Lixfeld <jason at lixfeld.ca> wrote:

> Yes, you only need one, except when you need more than one :)
> 
> OSPF is used so the CE routers can make use of the PE superbackbone.
> 
> iBGP is used to feed the CEs a full BGP table because IP transit customers hang off the same CE router and they expect a full BGP feed from us.
> 
> This is all iBGP because it's just a single step in a larger list of steps required to migrate a non-MPLS network into an MPLS network (without having to redesign the entire thing before I can bolt the old onto the new).
> 
> The RIB failures aren't causing any issues because the OSPF routes are taking precedence over their BGP duplicate counterparts, but it'd still be nice to tune the PE to not announce them towards the CE, if possible.
> 
> On 2012-02-26, at 1:42 AM, Tim.wall07 at gmail.com wrote:
> 
>> 
>> Yes I agree there is no need to have two routing protocols running between ce and pe you only need one and usually that routing protocol would be BGP 
>> 
>> 
>> On 26 Feb 2012, at 06:22, Xu Hu <jstuxuhu0816 at gmail.com> wrote:
>> 
>>> Don't understand why the protocol between CE and PE why need two, iBGP and OSPF? Two vrfs?
>>> 
>>> Thanks and regards,
>>> Xu Hu
>>> 
>>> On 26 Feb, 2012, at 11:35, Jason Lixfeld <jason at lixfeld.ca> wrote:
>>> 
>>>> Hi folks,
>>>> 
>>>> I'm wondering if anyone has some ideas they an share on this.
>>>> 
>>>> Assume the following:
>>>> 
>>>> - CE1 is speaking *iBGP and OSPF to PE1 inside vrf foo
>>>> - PE1 is mutually redistributing CE1's OSPF table with MPBGP
>>>> - PE1 exchanges MPBGP routes with PE2.
>>>> - PE2 is mutually redistributing CE2's OSPF table with MPBGP
>>>> - CE2 is speaking *iBGP and OSPF to PE2 inside vrf foo
>>>> 
>>>> So the problem is that the OSPF routes redistributed into MPBGP from via one CE are being announced to the other CE via the PE-CE BGP process.  Because those routes are already being received by the CE via the PE-CE OSPF process, they are showing up in the CE's BGP table as RIB failures.
>>>> 
>>>> Is there any way to filter those out?  I've tried setting and matching tags and communities from within various redistribution points on the PE, but I can't seem to keep them out of the CE's BGP table.
>>>> 
>>>> * I'm not sure how common it is to speak iBGP between a CE and a PE, so I figure I'd mention it.  It's not a typo, it's a requirement in this particular instance.
>>>> 
>>>> Thanks in advance for any clues..
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