"arp: packet with unknown hardware format"

[bob9744]

Hi all!

Upgraded to 23.1.2 earlier today, and I just noticed this via dmesg (never seen it before):

arp: packet with unknown hardware format 0x06 received on vlan01
arp: packet with unknown hardware format 0x06 received on vlan01

Any idea what might be causing this? I really didn't find any posts with the exact same verbiage, so I've no idea what's going on.

Thanks!

[bartjsmit]

Something outside the firewall on vlan01. Do a (promiscuous) packet capture on the relevant interface or subnet and 'go deep' with WireShark https://www.wireshark.org/ 

[bob9744]

Thanks for the reply! I did upgrade the firmware on one of my switches yesterday, and noticed as well that the switch my PC's tied in to showed a few bad packets from my PC - perhaps it was a temporary glitch in the matrix...

[carstenp]

Did you ever figure out what was causing this log entry? I am seeing the same on my firewall.