sundance-communications.com/forum Forums TDM Business Telephone Systems Inter-Tel Telephones & Systems DHCP Issue

Did you try pinging the IP's the server was trying to assign?

Yes and they are in use.

The bad thing is I am not sure what is using them.
It must be an old lease from the old dhcp server.

Immediately after you ping one of the IP's from a windows workstation you should be able to do 'arp -a' and see the MAC address for that IP. Of course Inter-Tel phones will all begin with 00-10-36. Anything else, the IP is used by some other device. You can try googling the first three parts to see what network chipset manufacture that device uses. That could be a clue.

You can also try Colasoft MAC Scanner. I think there is a 30 day trial version. MAC Scanner scans your ethernet segment and reports back all MAC addresses found, the IP if can be determined, the Workstation name, Workgroup name, chipset manufacturer ID, etc. It is a great tool for doing a quick inventory of your local ethernet network.

The DHCP tool I posted earlier will tell you all visible DHCP servers on your network. And of course there is always Wireshark.

If the IP phone firmware is new enough, you can connect to the IP phone in a web browser and there is a setting to mirror all IP phone ethernet traffic onto the PC port on the back of the phone. For the browser connection there is a custom TCP port # and login that I don't recall immediately.

If you can do that, then a PC with Wireshark plugged into the IP set PC port will display all of the network traffic to and from the IP set.

DH's post has great info, also try browsing and\or telnetting to those IP's. Alot of time its a printer and most of those have built-in web browsers.

Be sure you create an exclusion in yer DHCP server for those IP's until you figure out where these devices are. The broke fones should then come up as the exclusion will force the DHCP server to assign a new IP to the fone.