Cannot Find Dhcp Server When you do not use. ISP DNS server IP addresses, simply replace those IP addresses with your ISP DNS server IP addresses. * When you don’t know your ISP DNS server IP addresses, simply issue show dhcp server command on. DHCP is Dynamic Host Configuration Protocol. On a network configured with DHCP, the computers ask Aug 21, 2017  · How to Become a Freelance Writer. Hundreds of…