CPU utilizaton getting high in Cisco 4506 E

[manoj.kumar0074]

Hi all,

I experienced high cpu utilization in my chassies since last week.

For troubleshooting

As per the show process CPU output one of them process (Cat4k Mgmt LoPri) is taking max share of the CPU (80.51%).

And based on Show platform health output we got more details about consuming of CPU.

The processes consuming CPU are:

1.       K5L3Unicast Adj Tabl   2.00                                                           46%

2.       K5 L2 Hardware Addre   2.00                                                      59.12                                            

3.       PacketBufRaw              184.29     100%          184.29               100%

4.       PacketBufRaw             5938.31     100%         5938.31            100%

5.       IrmFibEntries           12288.00       0%           91.03                   100%

6.       IrmMfibEntryMemMan      13312.00       0%            0.40      100%

So I just want to know that how to resolve this and what is the Root cause for this?

As I haven't made any changes in my network topology.....

[Fabienne Stephanoff · Accepted solution]

Hello Manoj,

This process is typically related to the mac flapping (make sure mac-add notification mac-move is configured). You may want to look at STP TCN also (sh spanning-tree detail | i ieee|occur|from|is exec).

What version of code are you running? You may also want to check CSCsy32312. Not sure if it applies here.

Fab.

[network]

I know this is old but this post helped me solved this issue on a Cisco 4948. 

pvtsw02#show processes cpu | exclude 0.00
CPU utilization for five seconds: 98%/0%; one minute: 96%; five minutes: 96%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
57 8460610203189406815 265 4.63% 4.61% 4.79% 0 Cat4k Mgmt HiPri
58 9174777513404318891 269 93.59% 90.18% 90.75% 0 Cat4k Mgmt LoPri

I enabled `mac address-table notification mac-move`  and saw this over and over in `show logging` 

1y9w: %C4K_EBM-4-HOSTFLAPPING: Host 0C:C4:7A:AC:BD:27 in vlan 1 is moving from port Gi1/1 to port Gi1/5
1y9w: %C4K_EBM-4-HOSTFLAPPING: Host 0C:C4:7A:AC:BD:27 in vlan 1 is moving from port Gi1/5 to port Gi1/1

The host was not sending LACP Info so I could not port-channel them, this is a customers private switch so it seems they have this connected to the same server but those interfaces are sharing mac-address, probably a teamed connection but not sending LACP info.  I shutdown port 5 and now CPU usage is normal again. 

pvtsw02#show processes cpu | exclude 0.00
CPU utilization for five seconds: 6%/0%; one minute: 7%; five minutes: 23%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
57 8461043953189567640 265 2.95% 2.59% 3.02% 0 Cat4k Mgmt HiPri
58 9182727463404469312 269 3.03% 3.55% 19.40% 0 Cat4k Mgmt LoPri

Thanks!