RE: MSDP peer remote-as

If there's only one MSDP peer then the RPF check doesn't apply. You only need default peers if you have 2 or more peers that you don't want to run the RPF check on.

How RPF Check Rules Are Applied to SA Messages:
http://www.cisco.com/en/US/docs/ios-xml/ios/ipmulti_pim/configuration/12-4t/imc_msdp_im_pim_sm.html#GUID-2ACB5E5E-F70B-4795-8513-DB8208B76B88

Brian McGahan, 4 x CCIE #8593 (R&S/SP/SC/DC), CCDE #2013::13
bmcgahan_at_INE.com

Internetwork Expert, Inc.
http://www.INE.com

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Rati B. Jokhadze
Sent: Friday, December 20, 2013 12:20 PM
To: ccielab_at_groupstudy.com
Subject: Re: MSDP peer remote-as

if you're not using BGP as the tranport protocol , you must use "default" feature because of RPF check , either way rpf check will fail.

On 12/20/2013 08:52 PM, Sam Bibby wrote:
> I guess it's if you setup a MSDP peer with a BGP AS, but don't use BGP
> as the transport protocol:
>
> [STUF}-{R1}-----{R2}-----{R3}----{STUFF}
> BGP 10--}{------OSPF-----}{---BGP 20--}
>
> You can tell R1 who peers with R3 via MSDP that it's in remote-as 20,
> because if the peering is via BGP then the AS is learnt, thus pointless.
>
>
> I cant see a reason why you would use it to tell MSDP that the peer is
> in a different AS.....
>
> Not much help, but your point is true, it does seem kinda pointless.
> Unless it's something to do with the RPF check? I have had issues with
> MSDP over an OSPF backbone, it seems to like BGP for RPF reasons.
>
> \Sam.
>
>
>
> On Fri, Dec 20, 2013 at 4:41 PM, Matt Sherman <matt.sherman2_at_gmail.com>wrote:
>
>> Hi,
>>
>> What's the point of the "remote-as" option in the msdp peer configuration?
>> MSDP seems to work without it.
>>
>> Thanks,
>> Matt
>>
>>
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Received on Fri Dec 20 2013 - 14:29:14 ART