dev246
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Dell S4048-ON 100% CPU usage, Proccess KP and ifagt_1

Hi

I have 2 x Dell S4048-ON in VLT configuration. FTOS version 9.14(1.3)

And suddenly on one of my dell i sow very high latency to management interface. That dell have 100% CPU usage.

The process that cause 100% CPU are KP and ifagt_1

CPU utilization of sysdlp for five seconds: 80%/22%; one minute: 92%; five minutes: 92%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
0xb00b5020 609110 60911 10000 78.35% 72.57% 69.23% 0 KP
0xaff7b020 278100 27810 10000 0.84% 19.15% 23.12% 0 ifagt_1

CPU utilization of sysdlp for five seconds: 95%/39%; one minute: 87%; five minutes: 90%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
0xaff7b020 373370 37337 10000 71.14% 22.46% 18.52% 0 ifagt_1
0xb00b5020 958080 95808 10000 24.05% 64.44% 71.54% 0 KP

Anyone have idea what that processes do ? And what may be a problem.

That situation occurs 1 hour after last configuration change.

On that switch i don't have any layer 3 config (except management interface) . Only VLT + VLANs + Port channels.

Restart that switch doesn't solve the problem

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6 Replies
Moderator
Moderator

Re: Dell S4048-ON 100% CPU usage, Proccess KP and ifagt_1

Hi,

What was the configuration change?

Thanks,
Josh Craig
Dell EMC Enterprise Support Services
Get support on Twitter @DellCaresPRO
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dev246
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Re: Dell S4048-ON 100% CPU usage, Proccess KP and ifagt_1

Adding new port channel (in total i have 6 port channel no switch is almost empty).

Funny thing that yesterday i had no idea what cause problem so i unplug links to recently added switch (for that switch i create that last port channel), unplug SFP transceiver (not SFP+) for that switch, and problem was solved. CPU back to normal. So I thought something was with this new switch, but I decide to connect that switch again (this same sfp transceivers, this same ports, no configuration change) and the problem did not come back.

Any idea what happen? And what for is process KP and ifagt_1 ????

 

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Moderator
Moderator

Re: Dell S4048-ON 100% CPU usage, Proccess KP and ifagt_1

They are related to interface management, it sounds like it may have gotten stuck adding the new module.

Thanks,
Josh Craig
Dell EMC Enterprise Support Services
Get support on Twitter @DellCaresPRO
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dev246
1 Nickel

Re: Dell S4048-ON 100% CPU usage, Proccess KP and ifagt_1

Thanks for answer. This switch is not production yet so i can execute some command for you and replay with that command output or logs, So that you can prevent a similar situation in the future
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dev246
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Re: Dell S4048-ON 100% CPU usage, Proccess KP and ifagt_1

Hello

I have identified what causes the problem but I do not know why.

I have several SFP transceivers OPTON 125g-SM-DF31-LC-D, I known that is not in compatibility list and dell it does not guarantee that they will work with their switch.  But single Transceiver work fine, even several transceiver works fine but when i use two specific transceivers on in one switch CPU goes to 100%, when i use each separately everything ok. If I use this specific two transceiver in two different switches everything is ok.

So i can reproduce problem on demand, so even the are not dell transceivers maybe you will want to take a look at this because the problem is quite strange

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Moderator
Moderator

Re: Dell S4048-ON 100% CPU usage, Proccess KP and ifagt_1

Can you private message me the service tag and an email address to contact you?

Thanks,
Josh Craig
Dell EMC Enterprise Support Services
Get support on Twitter @DellCaresPRO
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