06-25-2008 07:51 AM - edited 03-05-2019 11:49 PM
Hello,
I've got two 6513 with dual sup 720.
One of the switch is at 95-96% for more 3 days.
I have taken a show proc cpu, show proc cpu history and done diagnostic with
http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a00804916e0.shtml
but I don't find anything
Here is the show proc cpu history :
1111111111111111 11111111111111111
9957382228226922942294299999900000000000000009999999900000000000000000
8994087697789187136762949989900000000000000009999999900000000000000000
100 ** * ******##############**********################
90 ** * * * * * **#*##################***##***#################
80 #* * * * * * **#############################################
70 ## * * * ** * * **#############################################
60 ##** * * ** * * *##############################################
50 ##*# * * ** * * *##############################################
40 ##*# * * ** ** ** *##############################################
30 ##*#********************##############################################
20 ##*#********************##############################################
10 #######*****##***#**##################################################
0....5....1....1....2....2....3....3....4....4....5....5....6....6....7.
0 5 0 5 0 5 0 5 0 5 0 5 0
CPU% per hour (last 72 hours)
* = maximum CPU% # = average CPU%
and show proc cpu sorted :
C6513-LTP1SL7-01#show proc cpu sorted
CPU utilization for five seconds: 82%/77%; one minute: 86%; five minutes: 87%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
9 20000572 28477236 702 2.39% 0.53% 0.51% 0 ARP Input
118 80264904 754410308 106 0.79% 0.78% 0.72% 0 IP Input
171 3799940 5226005 727 0.31% 0.23% 0.22% 0 CEF process
122 5001564 685722 7293 0.23% 0.17% 0.16% 0 Adj Manager
333 431608 26387383 16 0.23% 0.04% 0.00% 0 CEF RP IPC Backg
162 136288752 412771070 330 0.23% 0.30% 0.35% 0 DHCPD Receive
119 35436 319760 110 0.15% 0.01% 0.00% 0 MOP Protocols
114 576 297 1939 0.15% 0.11% 0.04% 1 SSH Process
113 1504580 4068144 369 0.15% 0.04% 0.04% 0 CDP Protocol
314 11376536 383070773 29 0.15% 0.24% 0.31% 0 Standby (HSRP)
124 1804984 3655920 493 0.15% 0.05% 0.05% 0 ARP HA
312 6214852 7147511 869 0.15% 0.20% 0.23% 0 MLSM Process
309 1194832 10882599 109 0.07% 0.05% 0.03% 0 IGMP Input
174 249384 4166130 59 0.07% 0.01% 0.00% 0 L3 Manager
Version is s72033-ipservicesk9_wan-mz.122-18.SXF10a.bin
Why the cpu is loaded to 95/96% ?
Thank you in advance.
06-25-2008 07:57 AM
mayby you have stp loop...
use
sh int | i rate
and pay attention to high PPS.
06-25-2008 10:07 PM
Thank you for your answer.
I will do this in the morning.
06-25-2008 11:50 PM
Hello,
I haven't got topology change on the network.
Regards.
06-26-2008 10:55 AM
do you have BGP running on the router&
Could you describe your router, what services are running?
06-27-2008 05:36 AM
Hello,
Thank you for your answer.
There is no BGP on the router.
I have opened a case and the engineer resolve my problem (very quickly!)
I insert the important informations, without named IP.
Action 1
From current show tech I can see that no interface is dropping traffic and also that lots of traffic is sent to the CPU to be software switched.
First of all we need to understand the nature of the traffic sent to the CPU.
About the trigger can you confirm that also this time High CPU occurred after having disabled mls qos?
Action Plan:
Please get me the following outputs:
Show clock
Show mls qos
Show process cpu sorted | e 0.00%
Sh ibc
Sh ip traffic (taken 3 times with ~30 seconds interval)
Show interface switching (taken 3 times with ~30 seconds interval)
Show interfaces
If during these captures CPU was still high (ONLY IF CPU WAS HIGH) please also perform a Debug netdr
Debug netdr capture rx
After 30 seconds undebug netdr capture
show netdr captured-packets - Please send me all the packets you captures this way.
Action 2
It seems that some traffic in vlan 5 (quite a bit) is being routed to the same interface it was received from.
Before giving you a possible solution I would like to verify my findings.
Please send me following outputs:
Sh ip route A.B.C.D
Sh ip cef A.B.C.D det
Sho mls cef lookup A.B.C.D
Sh ip route A.B.C.D
Sh ip cef A.B.C.D det
Sho mls cef lookup A.B.C.D
Sh ip route A.B.C.D
Sh ip cef A.B.C.D det
Sho mls cef lookup A.B.C.D
In any case traffic is always either sourced or destined from/to subnet A.B.C.D/24.
It would be great if you could also get me another CPU capture, this time in the other direction (previous capture was taken for traffic going TO the CPU now I would like to see the traffic coming back FROM the CPU).
deb netdr clear-capture (to clear the capture buffer)
Debug netdr capture tx
And again after a few seconds âshow netdr captured-packetsâ
NOTE: Please perform the previous netdr capture only after you verify that CPU is still high. So you run again a
SWITCH6513#Show process cpu sorted | e 0.00%
Action3
Actually all the prefixes are in the routing table.
You have a static route for X.Y.Z.A/24 and a default routes for the other prefixes.
All of them point to next hop A.B.C.D in same vlan.
Therefore packets enter the router in vlan5 through GiX/Y and exit in vlan5 though Gi5/16 > high CPU expected under this condition.
All the captures you sent me confirmed my findings.
You can lower CPU by issuing the command: mls rate-limit unicast ip icmp redirect 0.
That should solve this High CPU condition.
Anyway the question would be âwhy does the traffic follow this pathâ? Is this expected? Is it your design that requires that?
As you can see this kind of routing is not optimal.
Action plan:
Configure âmls rate-limit unicast ip icmp redirect 0â and check CPU utilization afterwards.
I want to congratulate the Cisco engineer which have found a solution.
Best regards.
06-26-2008 11:50 AM
Hi DWAM,
The CPU can run high if you have a long list of ACLs configured on the switch. Check if you can reduce the ACLs.
2. Try configuring " ip cef" .globally and on the interface carrying high traffic. This can help.
HTH
-rk
06-27-2008 05:37 AM
Hello rpratapa,
thank you wor your answer. You will find the solution on the previous answer.
Best regards.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide