All,
I have recently encountered interesting phenomenon:
On cisco 7206 working in a typical configuration in ISP environment
(BGP, ISIS, MPLS), I have noticed that traffic forwarded from
ATM interface (PA-A3-OC3) to T1 interface (PA-8CT1) is prone
to increased forwarding latency (up to 700ms!) while CPU utilization
is high (during typical spikes while BGP scenner or ISIS SPF runs).
This is happening only when forwarded packets are arriving as MPLS,
and egressing as normal IP HDLC frames. In other words, router is
removing MPLS label (penultimate hop).
As soon as I disabled tag switching on ATM, problem is gone.
IOS version is 12.2(8)T4.
Is it a feature or bug?
I can replicate it easily.
Thanks,
Przemek
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:04 EDT