I have blocked in my router DHCP for all wired channels and even put the range for the one left, the wireless one, from .60 to .65 and put static IPs for the devices I want to allow to connect. Now theres a wired device that always gets an IP with .53 without DHCP being active. How is that possible? How can I block this unwanted device from getting an IP?
A few obvious possibilities:
- the host has a statically configured IP address, thus not needing DHCP
- the host has an old DHCP lease which is still being used
- there is another DHCP server in your network providing the host with a DHCP lease
One thing to keep in mind: refusing DHCP requests from specific hosts does in no way block them from accessing the network.