arp: packet with unknown hardware format 0x00

[Rapboy2019]

Hi guys I need help on how to get read of this.

[Gertjan]

hi,

Locate the device that sends out rubbish, and locate a window. Throw the device through the window. If it's a Wifi device, put some effort into it.
You already know it's the interface called 'em3'.

[Rapboy2019]

@Gertjan I dont know where to start on how to trace it. do you have a guide or somthing that I can follow?

[Gertjan]

Something or some one on that interface em3 is sending very broken Ethernet packets.
Unhook the cable on your em3, or locate the device and have it repaired / removed.

[Rapboy2019]

@Gertjan that em3 port is hooked to my LAN switch and then hooked to all of my Ubiquiti AP's for serving internet wirelessly to my neighbors. someone said that I can trace those whos causing this using a packet capture, but I don't know-how. I hope you can help me, sir, or is there a way to disable that from appearing on logs, cause even though it happens our internet is working fine.

[Gertjan]

The issue isn't unknown.

See, fro example : arp packet with unknown hardware format 0x00 received on

The easy way : unhook one after the other the LAN's devices and check when the problem disappears.

edit :

If you get some 'hits' consider raising the "Level of details".
Before using the "packet capture" you should know what a packet is.
Normally, I would prescribe a 3 hours crash course on Youtube. The excel in explaining what Internet (actually : Ethernet) is. This knowledge is very useful, as you are an Internet user, and you are running a firewall/routers, who's job is : handling those packets. Maybe it's time you should know what it handles ^^
There is some good knew : it's not rocket science. Internet was build using the "keep it simple" concept. We just wanted something faster as the local post office services - and get fed up using the classic phone services.

[JKnott]

@Rapboy2019

After using Packet Capture, as described above, you can download the capture and view it with Wireshark to find the MAC address of the offending device.