We have a Domain controller (windows server 2012) in our LAN, there is also a DHCP server for clients to get them IP automatically.
all clients give right ip and dns configurations and work as well but these days we encounter a problem: some clients' DHCP configuration change to **use the following IP server ** unintentionally. and get some unknown DNS servers (172.18.x.x , 184.108.40.206)
- There are no any modem or dhcp server else.
- The users that login in clients don't have enough permission to change the configuration.