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RE: [mpls] MPLS with VRRP

  • From: <vinaychandra.sham@wipro.com>
  • Date: Thu, 30 Sep 2004 12:53:52 +0530
  • Cc: <mpls-ops@mplsrc.com>
  • Resent-Date: Thu, 30 Sep 2004 04:04:26 -0400
  • X-OriginalArrivalTime: 30 Sep 2004 07:23:53.0467 (UTC) FILETIME=[70804CB0:01C4A6BE]

Edward,

 

You are basically looking at layer 2.5 reliability through a layer 3 mechanism (VRRP). You can use fast-re-route extensions to RSVPTE to achieve this same functionality without using VRRP.

 

In the set-up given, the slave would reject all the RSVP-TE signaling message sent on the VMAC/VRIP leaving the salve in the cold about the tunnel. And when the failover happens the back-up router would drop the packets.

 

Regards,

Vinay.

From: mpls-bounces@lists.ietf.org [mailto:mpls-bounces@lists.ietf.org] On Behalf Of Qian, Edward
Sent: Tuesday, September 28, 2004 2:57 AM
To: mpls@ietf.org
Subject: [mpls] MPLS with VRRP

 

Hello,

 

Could someone please share any experience when setting up MPLS tunnels via VRRP routers?

 

Here is a tricky case:

I have a host connected to two routers (running VRRP as a virtual default gateway).

My host is actually MPLS capable (as a tunnel ingress LER) to setup TE tunnels via either one of

the two neighbor routers to a tunnel egress LER.

At my host, I choose to use explicit route with RSVP-TE ERO to set up such a TE tunnel. For the explicit hop list,

the first hop would be one of the VRRP routers, say I choose the master Router A (slave is Router B).

I should expect to happily send traffic out of my host through this TE tunnel via Router A if everything runs well.

Note that Router B has no knowledge of my TE tunnel.

 

Assuming Router A has a failure occurred, it is then expected that Router B should take over as a new master.

What would happen to my TE tunnel?  My host will keep sending labeled packets over the Ethernet frames

to the same virtual MAC which is also recognized by Router B. Router B, however, knows nothing about

the TE tunnel. So all the TE tunnel traffic will be dropped.

(or just imagining that Router B may even intelligently strip off the label and perform plain hop-by-hop forwarding to the destination,

that's to say all the packets are leaked out of my TE tunnel).

 

So my question is: Does VRRP really work with MPLS tunnels?

 

Regards,

Edward

 

-------------------------------------------------------------------

Edward Qian (edward.qian@tekelec.com)

Staff System Architect, Tekelec

Phone: 972-461-6349   Fax: 972-461-7506