7600 EoMPLS Subinterface - High CPU Utilization

Unanswered Question
Apr 19th, 2008
User Badges:


When I configure EoMPLS between subinterfaces on two 7600 the CPU utilization goes upto 70%. One box is running 12.2SXF5 and the other 12.2SRB2.

But when I configure on SVI to Subinterface or SVI to SVI there are no issues...

Has anyone faced similar problem?



  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
n.nandrekar Mon, 04/21/2008 - 21:27
User Badges:
  • Silver, 250 points or more


Can you check if the packets are getting CPU switched instead of h/w switched? In case of sub-interface mode EoMPLS, the label imposition is done by the PFC where-as in SVI based EoMPLS, the label imposition is done by the core-facing line card (SIP). So you might be seeing the difference, but it certainly would not be expected. Probably with portmode EoMPLS, the packets are hitting the CPU. This CPU utilization of 70% is seen with traffic right? Or even without traffic? also can you give details of your ingress LineCard and the egress LC?



prakashj Mon, 04/21/2008 - 22:52
User Badges:

Thanks Niranjan for your reply...

The funniest part is that the incoming interface (WS-X6816 with DFC3BXL) does not show high traffic..but the outgoing interface shows 10 times the traffic than the incoming one and keeps increasing...not sure where this traffic is coming from...we sniffed the CPU but nothing strange showing there...the outgoing interface is POS (1 port POS OSM). With SVI interface there is no problem..the problem appears as soon as we configure on subinterfaces...that too on both routers...

We have a TAC case pending as well..




This Discussion