I have a very small network of maybe two dozen machines, to which I've just added 7 IP telephones, talking to a Mitel controller on another site. I also have 2 ADSL links, using consumer ADSL routers. The 7 phones are on the same physical network as the PCs.

The 2 routers currently have internal IPs of and my existing machines all get addresses via DHCP and a default gateway of, but I would like the phones to have as their gateway. DHCP service is provided by a Windows Server 2003 box, currently set up with a single scope with a fairly basic set of options.

I've tried creating a different scope on a different subnet for the phones, but presumably because the Windows server isn't on that subnet DHCP just times out on the phones. I've also tried creating "Reservations" for the phones, but the DHCP MMC will not let me change the Router option for a reservation.

What's the trick I'm missing here?


Hmm we do something similar (not with phones) and we use DHCP reservations.

The GUI is a bit quirky in that you have to select the reservation in the left pane before you right-click on it and look at the properties, but you can definitely set the "router" DHCP value (and others) on a per-host basis.

  • So you can! Many thanks, I was trying to edit the setting in the right hand pane, which is obviously inherited and needs to be overridden through the left hand pane. Logical, really (!) – James Green Sep 14 '10 at 13:34

First off, you have two routers in the same range, The phones and their router should be in the same range. Realistically, you're best bet is probably to:

  1. Put the phones and their router in the
  2. Assign a secondary IP in that range to the NIC on the server say 1.253
  3. then hand out that range to the phones.

Windows DHCP seems to have some limitations requiring only one scope per subnet.

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