[j-nsp] Proper Break of MPLS RSVP Ring

[Levi Pederson]

All,

Double Checked the Layer 2 ring today and it seems solid.

Once again we have B and C co-located and A and D in remote locations with
a link between them.

Currently there is no RSVP between C and D and this is making my ring go
right instead of left!

I can Ping from D to C (it's next hop on the ring) if I force it out the
MPLS interface.  However when I ping the LSP interfaces (loopbacks) it
takes the long way around).  Short is 10ms and the long goes up to almost
26ms (pinging loops , again the long way around).  Current production
traffic backs this up.

This leads me to believe there is not a Layer 2 issue but something more
enigmatic.

Currently reading up on RSVP priority/preference but that seems like taking
a 2Ton Electromagnetic Sentient WreckingBall to hammer in a nail.

Thank you,






*Levi Pederson*
Mankato Networks LLC
cell | 612.481.0769
work | 612.787.7392
levipederson at mankatonetworks.net


On Thu, Jul 16, 2015 at 2:58 PM, Ben Dale <bdale at comlinx.com.au> wrote:

> Hi Levi,
>
> > On 17 Jul 2015, at 5:22 am, Levi Pederson <
> levipederson at mankatonetworks.net> wrote:
> > This is displaying it self in my output by not having an RSVP Neighbor
> > (neighbor down hellos sent) between C&D (and therefore sending my traffic
> > inefficiently 3/4 way around the ring instead of the 1/4 hop it could.
> > Last bit of information is that D sees C as a neighbor but is down.  C
> does
> > not even see D as a neighbor at all.
>
> This sounds like an L2 issue, or perhaps a misconfiguration - all nodes
> should be RSVP neighbours in order to be able to signal LSPs across those
> interfaces.
>
>


> Check your protocols rsvp config for the logical interfaces between D.
>
> Use monitor traffic interface <D-C interface> on D to confirm that RSVP is
> being sent out of the box.
>
> Check any control-plane filtering/firewall filters you have configured on
> C (though it seems to be receiving just fine from B).
>
> > I'm wondering how RSVP breaks that link.  All the documentation I can
> find
> > are focused on LSP validation/creation and not on Link Breaks to stop
> layer
> > 2 loops (is my assumption).  If one of my intervening links goes own I
> > would like to correct it and then move the break to the specified point.
> > But the RSVP documentation is rather...limited to only LSPs if I am
> reading
> > it correctly.
>
> RSVP won’t break the link to stop loops (the LSPs will carry service
> labels which may not even be L2 services), it will simply establish the LSP
> across the best/shortest path between endpoints (based on your TE
> settings), and if this becomes unavailable (and depending on your
> configuration) it will simply re-establish over any alternate path (which
> it sounds like is working well).
>
> Cheers,
>
> Ben
>
>