Kernel: IPv4: martian source 192.168.100.161 from 192.168.1.11, on dev enp1s0

So maybe 192.168.100.161 is the default IP of switch management?

I found a wifi router with that range of IP, I reset the router change the IP range but still apears that range 192.168.100.xxx but not many than yesterday.

Why reset? Why not remove or change ip address or even isolate it?
Is there any reason for that router into the network?

Remember: messages are not the issue, only the alerts of something that’s happening.
Issue (maybe) is the device, with flaws, misconfiguration or… something else.

@kristian1369
@pike

Hi
I can second that from Pike.
There may be more gadgets around you don’t even know about…

A very large retail shop here in Switzerland had a regional manager buy himself a WLan Box and plugged that into the enterprise Network. That WLan Box used the Enterprise Network as “Internet”, and created a new - very open - network. A backdoor to the retailers internal network.
So you say, ok, a retailer - but they are also an operating bank. With an unsecured WiFi Access to the LAN available from outside the building!
And no network manager knew about it!

Don’t kill the messanger of bad news - he’s only the messanger!

My 2 cents
Andy