I want to provide a DHCP service to my Windows 7 clients over a WAN connection to centralise DHCP. If the WAN link becomes unavailable I was expecting that as per scenario 2 (http://support.microsoft.com/kb/220874) that if the clients are restarted, they would maintain their current IP addressing so that they were able to access resources on their LAN. I have tested this in a pre-production environment and instead, the clients are provided with an APIPA address. I have checked that the default gateway is responding to ICMP. Can anyone explain how this can be achieved? Thanks Aidan

Hi, TO answer your questions: I want to provide a DHCP service to my Windows 7 clients over a WAN connection to centralise DHCP. It is impossible. Because DHCP server and clients communicates with broadcast. On an end point of any ISP you cannot send a broadcast package to another endpoint. If the WAN link becomes unavailable I was expecting that as per scenario 2 (http://support.microsoft.com/kb/220874) that if the clients are restarted, they would maintain their current IP addressing so that they were able to access resources on their LAN. This article only explains that if the system does not obtain an IP address either from DHCP or from manual settings, an IP address in 169.254.0.0 will be assigned by APIPA. For this feature, we do not do anything in Windows 7 because it is a built-in feature. I have tested this in a pre-production environment and instead, the clients are provided with an APIPA address. I have checked that the default gateway is responding to ICMP. Can anyone explain how this can be achieved? If you want to assign a IP address to a client on WAN, the best solution is connect the client to your site with VPN. Arthur Xie TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Sorry, I never made it clear. The WAN connection is a resilient VPN tunneled 'slow link' 2mb connection. I have had the DHCP helper IP address configured and I am able to provide addresses to the site. As there is a local file server, I would prefer that if for some reason the tunnel failed, any workstations that were restarted would maintain their previous address. The difficulty is that the clients (set to DHCP) will get 169 addresses whilst the server (on a static) will have a 10.x address and therefore be unable to communicate Thanks Aidan

Hi, I do not think that you need to enable DHCP client on server computer. That means you can assign IP address for a client and the VPN should still work. Do not need to change it after the VPN is disconnected. If you set “obtain IP address automatically” on a client, you are not able to change the IP address from the VPN server. Users must change the IP configuration themselves.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Sorry I think you are picking my issue up wrong Remote site with file server No local DHCP DHCP helper set to remote DHCP server Clients set to DHCP (10.44.2.x) Server with static address (10.44.2.100) When the site connection fails, Cannot reach DHCP server Clients get 169.x address Server has 10.44.2.100 adress They cannot communicate. I would like the clients to use their last good IP address as per scenario 2 (http://support.microsoft.com/kb/220874)

Hi, Sorry for delay in my response. Now we encounter a problem that when VPN connection fails, the default gateway may be still the VPN server since the VPN connection is not disconnected properly. Let’s confirm this situation. When testing, please enter “route print” in Windows 7 command line when the VPN connection fails. Please let us know the result. If the Default Gateway is not the server. When the VPN connection fails, you may be able to get the previous IP address after disconnect the VPN connection. Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.