I remember seeing a log message on a router (6500/7600 or GSR, don't remember) that was complaining about 8 labels on a packet. It was during a convergence and it was definitely not normal operation. We had FRR in the network, and there may have been some VCs as well over it. I looked the message up at the time, but don't recall it. I'll dig through old some logs if nothing else but for reference, it would be interesting to see how it happened.
On Mon, Sep 7, 2009 at 11:29 AM, Kaj Niemi <[email protected]> wrote: > > There isn't any real limit on the stack itself I believe. What matters is > sometimes how deep your equipment is able to look at the stack and at what > cost - on some (especially hardware) platforms this requires that the frame > is recirculated into the forwarding engine complex which effectively > reduces > your performance in half assuming worst case scenario... For example a 6500 > with PFC3B/PFC3BXL popping a explicit null label. > > If you're doing l3vpn you have at typically two labels (LDP/IGP, VPN) in a > network with both P and PE routers but can certainly have more: > > [FRR label][TE label][LDP label][VPN label] > > In the extreme case for AToM with CSC + TE headend + FRR (don't worry, not > on R&S, I think) you'd get five labels in the stack: > > [FRR label][TE label][LDP label][VPN label][VC label] > > On the other hand if you have a network of two directly connected PEs you'd > get by with only one label in both cases. > > As always you need to engineer the maximum MTU so that you have enough > space > for your largest expected payload. If you're into doing jumbo frames at > 9000 > bytes for customers I'd just max out at 9192 bytes actual MTU or so... And > if doing vendor interop this becomes a very interesting exercise of > calculating "least common denominator" MTU between all gear and cards in > use... :-) > > > > Kaj > > > > > From: Taqdir Singh <[email protected]> > > Date: Mon, 7 Sep 2009 05:52:28 -0700 > > To: <[email protected]> > > Subject: [OSL | CCIE_RS] how many labels can we attach ? > > > > some books say we can attach max. of 3 MPLS labels.. some say unlimited ? > > > > could anyone please give correct information ? > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > -- Bryan Bartik CCIE #23707 (R&S), CCNP Sr. Support Engineer - IPexpert, Inc. URL: http://www.IPexpert.com
_______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
