ping delay and drop packets of C2960L

[Rps-Cheers]

Hi everyone; These days,i have met a issue that is "ping delay" and "drop packets "on C2960L. Only ping SVI of C2960L,there will be a delay or a drop.The problem cannot resloved even though we replace another one C2960L,the problem will be fixed if we replace it to be a C2960S or a C3560 and so on.So,i guess there is a bug of C2960L.

[balaji.bandi]

Can you provide more inforamation :

what is the model of the switch

show version

show interface statstics

provide the problem evidence with the output where you see the issue ?

[Amine Nouasri]

The config could have been hardened to protect again icmp flooding. As BB said, post your config and some show outputs so we can help.

[Joseph W. Doherty]

You're pinging the switch itself? If so, Cisco devices give low priority to dealing with ping replies from their devices. It's not unusual to see ping delays or lost ping packets when pinging a Cisco device especially if it's at all busy processing traffic or doing more important tasks. (BTW, ping was originally designed just to check if a host was alive, it wasn't really designed to be a high precision performance measurement tool.) Poor ping results, from a Cisco device, often do not indicate any network or device performance issues. It's also not considered a bug.

Some Cisco device support a SLA responder function, which if enabled, and properly queried, will provide better latency measurements.

[Rps-Cheers]

Hi, Thanks for your response! Only the mgmt SVI have drop packets，and if repalce the 2960L to other deivces (eg.3750,2960S ...),There will be normal,we cannot resloved the issue even though we repalce it to another 2960L switch.

[Mark Malone]

Thats normal SVIs as Joseph stated ICMP is not prioritized in the backplane so the anything could be hammering it on the backplane and causing flutuations in responses
If you want to fix it , apply priority to the ICMP packets or ,use a proper test method like IP SLA or end to end testing , pinging a virtual interface with non prioritized packets you will never be guaranteed accurate results ,you could use CoPP if supported

[Rps-Cheers]

Hi Mark:
I have got .I also know the ICMP is not prioritized in the backplane,but same issue cannot display on other devices ( for example,Cat3750 and 2960S...).Do you think it is a bug of 2960L? Or is there any easy mothod?
Thanks