From: Ian Blaney (ian.blaney@gmail.com)
Date: Wed Jul 18 2007 - 12:45:04 ART
Mohamed
Sorry you have misunderstood my question.
This is not a real life scenario but just a question in my mind about how
OSPF works in a MPLS VPN setup. Why does an internal OSPF type 1 (o) on one
site always appear as a type 3 (IA) on another within a VPN. It is designed
this way. My question is really why is it designed this way?
Cheers
Ian
On 7/18/07, Mohamed, Liban [NTK] <Liban.Mohamed@sprint.com> wrote:
>
> Ian,
>
> Please make sure the SP is redistributing your OSPF correctly, so they
> need to match your internal routes.
>
> Test-router(config-router-af)#redistribute ospf xxx match ?
> external Redistribute OSPF external routes
> internal Redistribute OSPF internal routes)
> nssa-external Redistribute OSPF NSSA external routes
>
>
> Liban Mohamed
> NTAC-IP
> Sprint/Nextel
> www.sprint.net
> liban.mohamed@sprint.com
> (W) 678-291-3438
> (PCS) 404-441-9701
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Ian Blaney
> Sent: Wednesday, July 18, 2007 8:40 AM
> To: Cisco certification
> Subject: MPLS VPN - OSPF PE-CE
>
> Hello All
>
> I have a SP related question which hopefully someone can help me with.
>
> In a Layer 3 MPLS VPN where OSPF is used as the PE-CE routing protocol why
> are all internal routes from one site sent as inter-area routes to another
> site? I understand the concept that the SP core acts as the super backbone
> and the PEs are ABRs instead of ASBRs which would normally be the case
> when
> redistributing from one protocol to the other ie OSPF <-> MP-BGP.
>
> Surely the SP core should be as transparent as possible. The OSPF network
> type is sent in the extended communities attribute so it wouldn't be
> difficult for the egress PE to reconstruct the original OSPF internal
> route.
>
>
> Am I misunderstanding something here?
>
> Regards
> Ian Blaney
>
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