I manage a network of about 400 hosts out of a very large enterprise network. Recently we have been having some strange DHCP and DNS issues. It seems to have become a problem since the machines where migrated to AD from an NT domain. The machines are “locked down” Win2k on Ethernet, connected via Cisco 3500 switches and a 2600 router. The DHCP server is 5 router hops away in a different state. The issue we have run into is if a machine is left off for several weeks and turned on it will have an IP address conflict with another machine. It will refuse to release its IP address. The users do not have the right to run ipconfig /release or renew. It does not appear to work under administrator either. After a short time of being on the network both machines will complain about duplicate IP addresses and refuse to see the network. In several cases the only fix has been to leave the domain and rejoin. Also the IP addresses will resolve to different machine names, depending on which part of the building (i.e. switch) you are plugged into. My guess is that a DHCP request is being sent to the server which is timing out. It then assumes the IP is free and assumes its old IP. At this point should they request new IP addresses? If the security on the machine will not allow the IPCONFIG command to be run can the machine still request a new one? I do not have any sort of access to anything outside of my router, including the DHCP server. The “experts” in corporate say there is no problem and its something on our end.
Suggestions?
Kristopher
