[j-nsp] MPLS fast convergence without link information

[Phil Bedard]

BFD on the IGP session would be the best option.  We currently run ours at 300x3 on Juniper boxes and lower on some other platforms with better hardware processing of BFD packets.   If you are using aggregates something like 802.3ah may work better as BFD control traffic has a tendency to just take a single link on Junipers.  It is honor miss though whether L2 circuit provider can tunnel that traffic. 

Phil

On Dec 29, 2011, at 2:49 AM, Mark Smith  <ggglabs0 at gmail.com> wrote:

> Hi list
> 
> Let's examine an MPLS network where the connections between MPLS
> routers (P and PE) involve L2 devices. The connections might be leased
> L2 pseudowires or something similar. As a consequence the interface
> link state information cannot be used by routers to determine the
> state of the connection or neighboring router. For example consider
> routers A and B. If the connection between them is down, both still
> see interface (fiber or copper) link up. Similarly in case of failure
> of router A, B still sees interface link up. For the sake of
> simplicity, let's assume all routers are Juniper (e.g. MX series),
> IS-IS is used as IGP and RSVP(-TE) as the MPLS signaling protocol.
> 
> We would like to achieve the fastest convergence times safely available.
> 
> What is the current best practise to accomplish this and what order of
> magnitude are the convergence times?
> 
> I have spent some time searching for a solution. I have found these:
> 1) enable BFD on the IGP session
> 2) enable BFD on the LSPs
> 3) enable BFD on the RSVP session
> 
> Which one of them (if any) is the best solution?
> 
> I also read that BFD might cause IGP to reconverge instead of
> switching the traffic to bypass LSP (when using link-node protection).
> 
> Any help and pointers to good material is greatly appreciated.
> 
> Thanks
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp