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Large deviation on ICMP Echo reply / Catalyst 2960x

urcurcurc
Level 1
Level 1

Does anybody know whether the following phenomena is normal (based on IOS design)?

>Description

The time of ICMP Echo Reply from Catalyst fluctuates a lot.

>Network Layout

Server ---- 2960x-48

* These are directly connected and of course in the same subnet.

>Test Content

Perform pings from server to 2960x SVI and check their RTT.

>Result

23 packets transmitted, 23 received, 0% packet loss, time 22009ms

rtt min/avg/max/mdev = 0.466/3.331/13.468/4.391 ms

> Notes

i. No other physical ports are used, and CPU is NOT highly utilized.

Switch>sh proc cpu so
 CPU utilization for five seconds: 29%/0%; one minute: 29%; five minutes: 29%
  PID Runtime(ms)     Invoked      uSecs   5Sec   1Min   5Min TTY Process
  161      680049       97252       6992 15.06% 15.00% 15.00%   0 Hulc LED Process

<snip>

ii. I confirmed that the forwarding plane is normal; 2960x can forward packets without delay.

3 Replies 3

Philip D'Ath
VIP Alumni
VIP Alumni

ICMP is a low priority process.  The switch attends to ICMP when it is bored and has nothing else to do (aka is near idle).  I think this variation is acceptable.

Thank you, Philip. 

Glenn Martin
Cisco Employee
Cisco Employee

Moving this discussion to the LAN Switching forum. for faster response and greater exposure please ensure you're posting to the correct forum.

Thanks

Glenn

SMB Community Manager