[j-nsp] BGP/MPLS Question MX Platform

[Mark Tinka]

On 2/Aug/16 22:14, Dean Bolton wrote:

> Hi,
>
> I have a small network with 3 nodes that are connected in a "ring", ie A to
> B, B to C, C to A.  I'm running MPLS w/LDP for l2circuits and ISIS as the
> IGP.  MPLS is working fine including if one of the links fails.  Nodes A
> and C also have IP transit connections to upstream carriers and all three
> nodes have BGP setup.  What I would like to do is prevent BGP from using
> the A to C link for any traffic or only traffic that I specify and the A to
> C link only be used for MPLS.  I haven't quite been able to figure out how
> one could accomplish that since the loopbacks are reachable via MPLS and/or
> IGP and they will use that link during a failure of A-B or B-C.

If you use LDP as your label distribution protocol, this will be difficult.

I could see you solving this by using RSVP, but I'm only theorizing
this, as I'd be wary of having a partitioned MPLS network within the
same IGP domain. Strange things could happen if MPLS-switched traffic
ends up on a link that has no MPLS capabilities.

Mark.