Indeed, redistributing eBGP prefixes in the IGP would definitely work when 
send-label is specified by the 2 ASBR eBGP routers. Than you should have an 
end-to-end LSP between the PE's in both AS's.

Then you configure multi-hop eBGP VPNv4 between the PE's and that way 
distribute the VPN prefixes between the AS's, this is RFC2547bis Option C.

The only way of doing Inter-AS VPN's WITHOUT any VPNv4 communication is with 
Option A, which is a back-to-back VRF-lite configuration on ethernet 
sub-interfaces or multiple FR DLCI or ATM VC sub-interfaces.

-- 
Regards,

Rick Mur
CCIE2 #21946 (R&S / Service Provider)
Sr. Support Engineer – IPexpert, Inc.
URL: http://www.IPexpert.com

On 23 dec 2009, at 16:43, matt reath wrote:

> I've run into lab scenarios where an InterAS VPN needed to be established w/o 
> using the VPNv4 family between the eBGP neighbors. To get it to work properly 
> I configured send-labels on the eBGP neighbors and made sure that each AS 
> knew about the other AS's loopback addresses via BGP<->IGP redistribution.  
> That way there is a label defined via LDP/IGP in each AS for the other ASs 
> loopack addresses. I used next-hop-self on the iBGP neighbors but it still 
> wouldn't build a complete LSP unless the other AS's loopbacks were 
> redistributed.
> 
> On Mon, Dec 21, 2009 at 6:21 PM, Rick Mur <[email protected]> wrote:
> Try and convince yourself why you would need to add the send-label. See what 
> you are doing and if you know that the next-hop prefixes already have a label 
> through IGP/LDP or do you need to allocate labels for the EBGP prefixes, it 
> really depends on your implementation just like Bryan said. If next-hop-self 
> is used for EBGP prefixes than the next-hop address already has a label 
> allocated through the IGP and LDP, so no then you don't need send-label.
> 
> Really convince yourself of doing something, rather than doing a 'best 
> practice'. See how the LSP works and how things are allocated.
> 
> -- 
> Regards,
> 
> Rick Mur
> CCIE2 #21946 (R&S / Service Provider)
> Sr. Support Engineer – IPexpert, Inc.
> URL: http://www.IPexpert.com
> 
> On 21 dec 2009, at 21:35, Bryan Bartik wrote:
> 
>> Srinivas,
>> 
>> If you are doing MP-EBGP between the ASBRs and using next-hop-self from the 
>> ASBRs to the internal peers, then you shouldn't need send-label at all. In 
>> this lab, NHS is configured in the PG so I think send-label is unnecessary.
>> 
>> If you didn't use next-hop-self then you need to get that ASBR link into BGP 
>> and use send-label from ASBR to IBGP peers.
>> 
>> On Mon, Dec 21, 2009 at 1:08 PM, srinivas pv <[email protected]> 
>> wrote:
>> Hi Team,
>> 
>> I am doing this lab and I have the following query. Please do the needful.
>> 
>> This is inter-AS scenario, and the restriction is not to allow LDP on any 
>> interconnecting links between networks.
>> 
>> So we need to use send-label on the links between AS 100 and 200. Why do we 
>> need to configure send-label for iBGP neighbors also?
>> Is interconnecting links means, here iBGP also?
>>  
>> 
>> Thanks,
>> Srinivas
>> 
>> _______________________________________________
>> For more information regarding industry leading CCIE Lab training, please 
>> visit www.ipexpert.com
>> 
>> 
>> 
>> 
>> -- 
>> Bryan Bartik
>> CCIE #23707 (R&S, SP), CCNP
>> Sr. Support Engineer - IPexpert, Inc.
>> URL: http://www.IPexpert.com
>> _______________________________________________
>> For more information regarding industry leading CCIE Lab training, please 
>> visit www.ipexpert.com
> 
> 
> _______________________________________________
> For more information regarding industry leading CCIE Lab training, please 
> visit www.ipexpert.com
> 
> 

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