We have three 7609 with identical hardware configurations, with two of them having normal CPU usage while the third one sees high CPU usage due to IP Input and Tag Input processes. All three machines are running 12.2(18)SXF8 (s72033-adventerprisek9_wan-mz.122-18.SXF8.bin).
Here is what the problematic box shows: maribor3#show proc cpu sort | ex 0.00 CPU utilization for five seconds: 24%/13%; one minute: 31%; five minutes: 30% PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process 208 102757464 739213274 139 5.27% 4.69% 4.66% 0 Tag Input 124 2740496481519913035 180 3.67% 3.56% 3.48% 0 IP Input 8 21967708 71492385 307 0.79% 1.04% 1.12% 0 ARP Input 3 6272 7325 856 0.31% 0.02% 0.05% 1 SSH Process 170 3917100 305983 12801 0.31% 0.20% 0.22% 0 Adj Manager 176 1857240 1022835 1815 0.23% 0.09% 0.08% 0 IPC LC Message H 130 2376768 7121174 333 0.15% 0.16% 0.14% 0 ARP HA 333 2042400 7425874 275 0.07% 0.08% 0.07% 0 BGP Router 181 1069940 2486998 430 0.07% 0.07% 0.06% 0 CEF process 332 1001612 3902572 256 0.07% 0.03% 0.04% 0 OSPF Router 1 The ok box shows this: ljubljana9#show proc cpu sort | ex 0.00 CPU utilization for five seconds: 9%/6%; one minute: 15%; five minutes: 14% PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process 45 88 105 838 1.59% 0.12% 0.02% 2 SSH Process 8 17520028 76102308 230 0.87% 1.00% 1.03% 0 ARP Input 124 18549000 143423921 129 0.71% 0.87% 0.82% 0 IP Input 170 2844936 305695 9306 0.23% 0.22% 0.23% 0 Adj Manager 86 222176 303204 732 0.07% 0.03% 0.01% 0 Compute load avg The Tag Input and IP Input processes rarely go below about 3-4%, while the other boxes usually hover just below 1%. The "Troubleshooting High CPU Usage" document from Cisco did not help identifying the cause. While I can understand the possible reasons for high CPU due to IP Input (traffic being process switched due to misconfiguration), I don't see how this could happen for Tag Input, which I guess is handling MPLS. What kind of misconfiguration could cause process switching of MPLS? The box in question runs a heavy mix of typical ISP traffic (IPv4, just a little bit IPv6, BGP, OSPF, MPLS L3 VPNs, multicast). The only difference in used protocols between the problematic box and the others is IPv6, but I have already tried to temporary completely shut off IPv6 with no visible difference. The IPv6 configuration does contain tunnels, which are probably process switched, but the traffic is so small (almost nonexistant) that it shouldn't affect CPU usage at all. Has anybody experienced this, especially the high CPU usage due to Tag Input process? _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
