Hi all ... An urgent help is required and highly apreciated ... Am running a network of 15 Workstation (XP Prof.) ... I used to have Windows 2000 on the server. We have formated the server and Installed Windows 2003 Server / Service Pack 1. As well Installed the ISA 2004. All on a DELL machine (DIMENSION 2400), Intel(R) Pentium(R) 4 CPU, 2.66 GHz, and 512 MB Ram. ((I know abusing such a machine by setting it as a server is a bad thing)). On the new configuration DHCP and DNS has been configured. But I noticed that the DHCP does not work normally. The Server refusess to connect the LAN to the Internet. So the whole LAN is taking the Internet connection at the moment directly from the Modem. Thus, the server has no control over the LAN beside the Connecting and Disconnecting of the Internet Service. I guess that I have some problem with the configuration of the DHCP. Your help is highly appreciated. Specially with directions and remarks of HOW-TOs. Thank you so much in advance.

How do you expect DHCP to work? (you said it does not work normally, but how would have expected it to work and how did you configure it ?)Is the modem connected to the server or directly to a network device?

Checklist: Connect your modem to a switch, connect your outside NIC from your ISA to the same switch. Connect your inside NIC to the LAN-switch. This makes sure that your clients can't use internet without going through the ISA. Configure your ISA to route traffic and create the rules you want to apply. If your modem supplies DHCP-addresses, turn that off. Make sure to authenticate your DHCP in AD and check that the scopes are correctly configured.

<Not a deployment issue. Moving to Platform Networking forum.>

Here's a link to the guidance we have posted on how to configure and manage Windows Server DHCP: http://www.microsoft.com/technet/network/dhcp/default.mspx#E6C Also, can you switch off your ISA Server and see if that makes any differences? As others have mentioned, did you Authorize the DHCP Scope? That one always gets me too.