Problems with rate-limit flood unknown-destmac causing slow traffic

[javfe]

We have detected that some users are experiencing slow traffic, specially while they are uploading files to a shared server (located in the same vlan as the computer or in different vlan). They upload the files both via Windows smb or via sftp. Once they start to upload the files we have detected that after a while the “Unknown-dest-mac flood” counter increases dramatically and the switch reach the rate-limit configured (1000 pps in the UP-LINK port and 120 pps in the users ports) and so it starts to drop packets, causing the slowness in the traffic and uploads.
 

Regards

Javier

[javfe]

Hello Stefan,

I don’t know the status of the server. No problems are identified in the traffic captures

[StephanH]

Hello javfe,

if your server has more then one network interface, as first steprepeat the test with only one enabled.

[Stefan_K_]

Is the server virtualized?

Do you see anything strange in Wireshark on the client?