[nsp] ESR 10008 MPLS Tunnel woe

[Nic McCartney]

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net]On Behalf Of Eric Osborne
Sent: 25 April 2004 00:20
To: nic at gblx.net; 'Cisco-Nsp'
Subject: RE: [nsp] ESR 10008 MPLS Tunnel woe




 > -----Original Message-----
 > From: cisco-nsp-bounces at puck.nether.net
 > [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Nic McCartney
 > Sent: Saturday, April 24, 2004 4:47 PM
 > To: Cisco-Nsp
 > Subject: [nsp] ESR 10008 MPLS Tunnel woe
 >
 >
 > Dear all,
 >
 > Here is my network topology :-
 >
 >  [7513a]<--pos-->[ESR10k]<---ATM--->[7513b]<--pos-->[7513c]
 > 12.0(25)S1       12.0(25)S1         12.0(24)S     12.0(25)S1
 >
 > I have a pair of tunnels, one ESR10K > 7513b and t'other
 > 7513b > ESR10K. When I send traffic from 7513c to 7513a then
 > I see the traffic use the tunnel I have set up between 7513b
 > and ESR10K (interestingly when I send a high number of pings
 > it takes a full 7 seconds for the Tunnel stats to show that
 > anything is passing).


. 7 seconds on the 7513, or on the 10k?  Or both?  Often this delay is
because
. the LCs (which keep the packet counters in a distributed-forwarding system
. like the 7500) only periodically send packet counter updates to the RP.  I
. know this is true on the GSR; the stats period is like 5 or 10 seconds.
. Should be about the same on the 7500, but not the 10k.

7 seconds on the 7513, afterwhich the stats increment fine.
The 10K shows no packets incrementing at all.

 >
 > When I send traffic from 7513a -> 7513c then I see my pings
 > go OK but the traffic does not appear to be going over the
 > tunnel ESR10K->7513b. By this I mean the stats do not show
 > anything. The tunnel stats are all zeros. Funny thing is
 > this, if I am on ESR10K and ping to 7513c then the Tunnel
 > stats *do* increment. If I do sh ip rou <dest_ip> on ESR10K
 > then it shows the Tunnel as the chosen route. It is indeed a
 > most perplexing mystery. Anybody seen this before?
 >

 Since it's only a one-hop tunnel (at least from the picture), it sounds
. tricky to show whether this is a counters thing or whether forwarding
isn't
. right.  What do CEF and the 10k HW forwarding think about the forwarding
. entry for the dest ip addr?  Are there any counters incrementing on the
ATM
. interface on either headend router?

Yeap, tricky indeed. ATM stats are incrementing with no problems at all.
CEF on the 10K shows the tunnel is the interface to use and so does
the 7513.

Nic