I am running dual-homed ISA Server (standard) which one NIC on a fixed private IP, and the second NIC set to DHCP attached to a cable modem. My ISP issue 4 hour leases. My problem is this, during bootup the machine requests and accepts a DHCP offer without problem, however once the machine has fully booted it is unable to renew the lease. Thus, the server needs booting every 4 hours. I have looked at the traffic on the Public NIC using network monitor, and can see the DHCP Offer packets, I believe ISA Server is stopping them coming through. The DHCP Client packet filter is ENABLED. I have tried applying ISA SP1, but that errors with "ISA Server not installed" ! Any suggestions which don't involve rebuilding, greatly appreciated. Cheers, Joel. P.S. Due to a funny during installation, the system drive is on F:. This e-mail has been scanned for all known viruses by Star Internet on behalf of The Instrumental Media Group. Whilst every care has been taken to ensure this message is virus-free, neither Star Internet or The Instrumental Media Group can be held responsible for any virus it may contain.