topic Re: Dropped Pakets UC Egress queues on ICX7850 Stack in ICX Switches

Dropped Pakets UC Egress queues on ICX7850 Stack

Darky — Thu, 06 Mar 2025 08:36:26 GMT

Good Morning Community,

i have a problem with dropping pakets in the UC Egress queues.

Traffic comes in with 25GB and goes out with 10GB.

I think that could be the reason for queuse overun (traffic comes only burst (iscsi)) not fully load.

Is there any recommended tununig option to increase the buffer for that queues or is there a other solution available?

Thanks for helping

Re: Dropped Pakets UC Egress queues on ICX7850 Stack

MariaC862 — Wed, 12 Mar 2025 15:12:59 GMT

Hello!

Thank you for your post, I think this might help you:

To mitigate the packet drops during this event, change the egress buffer in the port for Queue 0 to use more of the available buffer in the Sharing Pool.

To change the Egress buffer in the 40G port to use more of the available buffer in the Sharing Pool, use the following commands:

qos egress-buffer-profile

queue-share-level level queue-number

The default share level for Queue 0 is level4-1/9.

For Example:

(config)#qos egress-buffer-profile 40G-Port queue-share-level level5-1/5 0 --------> In profile 40G-Port use 1/5 of the available sharing buffer in queue 0

(config)#interface ethernet 1/2/1

(config-if-e40000-1/2/1)#egress-buffer-profile 40G-Port ----------> Apply it in the port having the drop

(config-if-e40000-1/2/1)#sho qos egress-buffer-profile 40G-Port -------> To check that it has been applied
Egress Buffer Profile: 40G-Port
Ports attached:
1/2/1
Per Queue Details:       Share Level:
Queue 0                  level5-1/5
Queue 1                  level3-1/16
Queue 2                  level3-1/16
Queue 3                  level3-1/16
Queue 4                  level3-1/16
Queue 5                  level3-1/16
Queue 6                  level3-1/16
Queue 7                  level3-1/16

Detach Egress buffer profile

We must configure the 'no egress-buffer-profile' command to detach a profile from any ports that are using it before we can configure the 'no qos egress-buffer-profile' command to delete it.

The following example detaches the egress buffer profile named port-40G from port 1/2/1 and then delete the profile.

Device(config)# interface ethernet 1/2/1
Device(config-mif-1/2/1)# no egress-buffer-profile port-40G
Device(config-mif-1/2/1)#exit
Device(config)# no qos egress-buffer-profile port-40G

Note: The above command is not supported in ICX7150

I hope that works!

Re: Dropped Pakets UC Egress queues on ICX7850 Stack

Darky — Wed, 19 Mar 2025 06:06:43 GMT

Hello Maria, looks good - seems it helps. I will checkthis a week then come back with more results.

best regards

Re: Dropped Pakets UC Egress queues on ICX7850 Stack

Darky — Wed, 19 Mar 2025 13:43:27 GMT

mmm looks like fewer packets are being lost, but there are some new ones again ...

Is there any more config possible to fix the problem?

Re: Dropped Pakets UC Egress queues on ICX7850 Stack

MariaC862 — Thu, 20 Mar 2025 20:42:01 GMT

Hi!

Thank you for your reply, for further troubleshooting we need to collect more info and evidence, I highly recommend opening a ticket with our support team.

Open a ticket here.