Re: ospf with vrf

This one has caught me a number of times, and I would say it is because
those "pe checks" are not well understood.

Those checks can invalidate a route (clear the routing bit) of a
downward route, but only take place if the router has the OSPF process
attached to a VRF (be it part of MPLS or not).

If you are confused, I would recommend you play some time with this.
Some things to consider: where do you need vrf-lite, what happens with
sham-links in this scenarios, what happens when CE-PE are not in area 0
and you have an area 0 elsewhere...

-Carlos

Yuri Bank @ 17/06/2012 04:03 -0300 dixit:
> It depends, what area is your CE-to-PE adjacency in?
>
> Remember a router will not use IA routes learned from a none backbone area
> IF it's an ABR. When you create a VRF-OSPF instance, it automatically
> becomes part of the MPLS Super backbone, essentially part of Area 0. This
> is why the 'capability vrf-lite' feature is needed. It removes the router
> from the Super backbone, meaning you can now install Type 3 LSA information
> into the RIB, learned from none backbone areas. It also disables the
> Down-bit check.
>
> -Yuri
> On Jun 16, 2012 9:09 PM, "Aaron" <aaron1_at_gvtc.com> wrote:
>
>> I think I found the answer, although I don't fully understand it all yet.
>> I
>> have heard about this before and recall some of it.
>>
>> This seemed to do the trick...under, router ospf vrf testvrf "capability
>> vrf-lite"
>>
>> I read this. https://supportforums.cisco.com/thread/202402
>>
>> Apparently it has something to do with loop prevention and "pe checks" of
>> domain id and down bit or something like that to keep pe from adding
>> anything other than type 1 and 2's to rib.
>>
>> Aaron
>>
>> -----Original Message-----
>> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
>> Aaron
>> Sent: Saturday, June 16, 2012 10:15 PM
>> To: 'Ccielab_at_groupstudy.com'
>> Subject: ospf with vrf
>>
>> why does my pe lose the ability to add type 3 (summary) routes to its rib
>> AFTER I convert its ospf process to vrf ?
>>
>>
>>
>> in other words, when my pe's ospf process does not have vrf config I see
>> the
>> IA routes to other areas, but as soon as I change my ospf process to vrf I
>> lose my IA routes. They are still in the ospf db though, but just not
>> being
>> added to the RIB.
>>
>>
>>
>> Aaron
>>
>>
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-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net