Ticket Number: HEA-NOC/20070130-7 Ticket Status: UPDATE
Ticket Type: unscheduled Resolver:
Ticket Opened: 20070130 18:14 UTC Problem Start: 20070128 22:00 UTC
Ticket Update: 20070206 10:04 UTC Problem End:
Site/line: Citywest PoP
High cpu usage on core router in Citywest.
Currently this is not service effecting. However there will be a loss of
resilience if the router fails over
20070130 18:07 COC Contacted Lancomms. Awaiting response.
20070206 09:50 PC - Carried out some debugs on multicast traffic and
found that cpe1-oir was continuously sending a high rate of pim
register messages (unicast encapsulated multicast) to cr1-cwt.
This should only happen for brief periods and explains the high PIM
CPU useage on cr1-cwt.
After limiting the generation of these messages on cpe1-oir the
5 min total CPU utilisation has dropped from around 36% to 16%.
The route processor had previously been dropping large numbers
of packets from g4/0 (traffic sent via the TCD POP) and this has
The PIM utilisation is now 1.5, which is still higher than expected
and so further troubleshooting will be required. cr1-cwt does seem
to be sending register-stop messsages to cpe1-oir, but the latter
is either not receiving or ignoring them.
This ticket can be monitored at http://www.hea.net/tickets/20070130-7