+ 0 Votes Give the modem a static IP gechurch January 21, 2013 at 10:39am PST So your modem will still be doing the dialing, but you want the server to do DHCP/DNS? If so what you want to do is: - Set the modem with a static IP (192.168.0.1). - Disabled the DHCP server on the modem. - The modem will still need DNS servers (since it's got a static IP it won't be given the DNS servers your DHCP server is handing out). You can either let the ISP push down the DNS settings, or can use 22.214.171.124/126.96.36.199. - Enable DNS and DHCP on the server. - Configure DHCP to dish out 188.8.131.52 and 184.108.40.206 as DNS servers, and your modem's IP (eg. 192.168.0.1) as the default gateway. - Lastly, make sure 192.168.0.1 and any other static addresses you are using are not in the DHCP address pool. + 0 Votes Reponse To Answer gechurch February 3, 2013 at 6:56am PST That's excellent to hear Matt. The loopback address sounds normal. I administer Windows SBS boxes and best practise with these is to specify a single DNS entry, which should point to the SBS box itself. I normally enter the servers IP address, but when I go back in later a lot of boxes tend to have 127.0.0.1 set. Windows is probably changing it after it realises it is it's own address. Perhaps they found people would change their IP and forget to update the DNS entry, or perhaps it's slightly faster to use the loopback address. + 0 Votes Home AD DS/DHCP/DNS server MattCollinsUK January 21, 2013 at 6:48pm PST Hi gechurch, Thank you for your reply. The modem will be the interface between the server and the Internet. When I set the modem into modem only mode it gets an IP of 192.168.100.1 So with that in mind, I am proposing the following settings to be set on the server. IP address 192.168.0.1 or 192.168.100.1 (not 100% on this) Subnet Mask 255.255.255.0 Default Gateway: 192.168.100.1 Use the following DNS server address: Preferred: 220.127.116.11 (or ISP) Alternate: 18.104.22.168 (or ISP) Thank you in advance. + 0 Votes Home AD DS/DHCP/DNS server MattCollinsUK January 24, 2013 at 6:30am PST Hi gechurch, Thank you very much for your advice so far. I have tried the above, and have successfully managed to be able to get clients to pick up DNS settings, join the domain, and I can administrate in AD, log on as domain admins etc etc. However neither the server nor the clients have internet access. Even if I leave the IP settings automatic (while the modem is in mode mode) I still cannot get onto the internet (with the modem plugged directly into the server) I have tried putting the various settings in as follows: IP = 192.168.100.2 Subnet = 255.255.255.0 Gateway = 192.168.100.1 DNS I have tried 192.168.100.2 and 22.214.171.124 and 192.168.4.100/192.168.8.100 (the modems DNS server) I seem to be so close, I + 0 Votes Home AD DS/DHCP/DNS server MattCollinsUK January 25, 2013 at 2:42am PST Thank You, Once the modem is in modem mode, with the built in DHCP server off, i cannot ping or use any of the advanced tools. However when the modem is in normal mode, the internet works fine. While in modem mode, i can ping 192.168.100.1 and that works fine. My network is modem---switch---devices (pc,pc,laptop,laptop, ps3,wifi access point, server) On rare occasions, (like now) my pc (not server) can actually work when the device is in modem mode. With all the settings left automatic, i get the following information from a ipconfig /all (from my pc) I have inserted a few "x's" for security in the first two bits, of the below ip's Connection-specific DNS Suffix . : Link-local IPv6 Address . . . . . : fexx::xxb0:bxxx:96d7:1551%12 IPv4 Address. . . . . . . . . . . : xx.xx.43.249 Subnet Mask . . . . . . . . . . . : 255.255.252.0 Default Gateway . . . . . . . . . : xx.xx.40.1 Can these settings be used or helpful in anyway? Thanks. + 0 Votes network configuration should look like this Who Am I Really January 28, 2013 at 3:00am PST ISP line in > modem > router (optional but recommended) > server > switches > LAN clients / devices for DHPC from the server to work correctly, the network has to be setup with all clients on the down stream side of the server the server should have 2 NIC jacks one will be used for the WAN the other will be used for the LAN otherwise with your current configuration everything is trying to communicate directly to the modem instead of passing through the server with everything directly connected to the modem when the server handles DHCP it's not going to function correctly because it can't forward the traffic back into the same LAN trying to reach the WAN also when a modem is setup in modem mode, which disables the router portion of the modem only one client can be connected at any given time which is why automatic settings work + 0 Votes Home AD DS/DHCP/DNS server MattCollinsUK February 2, 2013 at 7:16pm PST Thanks Gechurch, Your advice worked perfectly, turning the DHCP server off on the modem, worked. All clients now request DNS and DHCP from my server. A strange thing I have noticed the server auto configure is that, the DNS settings on the server has changed to 127.0.0.1 which I understand is the loopback address, which in a way makes sense as itself is there DNS server. I do now have a separate NIC on my server, but I am using that solely for HyperV traffic on a private switch, so I can play/practice without interfering.