Hi Roger,
> draft-ietf-l3vpn-rfc2547bis-01.txt specifies the multi-AS Backbone
> scenario.
>
> 10. c) Multihop EBGP redistribution of labeled VPN-IPv4 routes between
> source and destination ASes, with EBGP redistribution of
> labeled IPv4 routes from AS to neighboring AS.
>
> The ASBR maintains labeled IPv4 /32 routes to the PE routers within
> its AS and uses EBGP to distribute the labeled routes to other ASes.
>
> Between, two ASs, it uses BGP to distribute the labels, but in that
> case, how is the labeled path within the AS Maintained. Is it using
> BGP itself. Or is LDP/RSVP used to
> distribute the labels within the same AS?
Redistributing the eBGP-learned /32 into your IGP (thus using LDP/RSVP)
works. A colleague of mine has tested this. Obviously this has some
limitations with scalability.
As you said, this could have some scaling limitations. Does LDP assign a label to each route learnt by the IGP. I think, LDP does not assign labels for BGP Learnt routes. Can cisco be configured to send labels for some BGP Learnt routes?
Using iBGP IPv4+label - haven't tested yet as no IOS for 7600 (our PE
plattform) was available supporting this. As I understand the theory
this results in a packet with 3 labels minimum: the MP-BGP VPN label at
the bottom, then the IPv4 next hop label and topmost the LDP label to
the ASBR.
The IPv4 Nexthop Label (Middle one) would be assigned by the ASBR?
Regards,
Roger
Regards, Marc
--
Marc Binderberger Powered by *BSD ;-)