I found, that sometimes DHCP server from behind my main router answers DHCP request from clients in the
LAN. Below is an example
Notebook is connected to
LAN via access point. There is DHCP server running on
pfSense. There is also
DHCP server running on
Router3. Sometimes, notebook receives address from
The question is: how it can be and how to patch this bleach?
In my firewall I have a rule
192.168.100.0/24 to pass so that I could open router web GUI from any clients. But I don't want it's DHCP server serves...
Probably I was wrongly blaming
Router3 device. I found another device that could provide
DHCP services: I have also multimedia player with built-in
AP functionality. I have turned it on some time ago, but it didn't worked as I expected, so I forgot about it. Although it has
DHCP server inside. I deduced this by
MAC address of that fake
DHCP server, which has first bytes the same as of this device. Now I turned
AP off and will see how it will behave.