Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We currently have Active Directory running on a Windows Server 2003 box, with ranges of 192.168.1.x and 192.168.2.x

As we have a lot of users vpn'ing into the network we end up with a lot of calls for assistance when their modems IP ranges conflict with ours, and we only see this problem getting bigger

We've been looking to change our IP range to 10.61.x.x, however we've been told that AD does not like this at all..

  1. What problems can occur when changing the IP range with Windows Server 2003 AD?
  2. What steps would you recommend to change the IP range of a Windows 2003 network?

Thanks for any assistance!

share|improve this question
to be clear active directory does not have an IP range. Your issue is a routing problem not an AD problem. Fix that and you won't have to change anything on your local network. – tony roth Sep 6 '10 at 22:23
also the more I read this the more frustrated I get with the so called answers below.. If you have you vpn infrastruture setup correctly it won't matter what ip's your user use. – tony roth Sep 6 '10 at 22:25
Thanks for everyone's feedback, seems like there are two options, 1) change our vpn routing (been advised that because of our setup that is extremely painful to modify), 2) change the IP addresses in DNS (will try and find out why this is a big problem with Windows Server 2003, as that seems to be the issue...) – Andrew Bickerton Sep 7 '10 at 9:11

This isn't really a problem. Just make sure your DCs' IP addresses get updated in DNS. You may have to update some records manually. As long as all the DCs can talk to each other, all the workstations will update their own DNS records which will replicate to all DNS servers in the domain.

When you're done, make sure your DCs are syncing with each other.

share|improve this answer

In addition to what Jason has said, make sure to check\change the following:

check\change the ip address that the DNS service is configured to listen on.

check\change the ip address that the DHCP service is configured to listen on if you're using DHCP. In addition you'll need to modify your scope to use your new ip address range and you'll need to change some scope\server options such as the router option.

check\change the ip address that the WINS service is configured to listen on if you're using WINS.

Create a new reverse lookup zone in DNS for the new address range.

check\change your subnets in Active Directory Sites and Services.

check\change the ip addresses and settings on your switches, routers, firewalls, VLAN settings, printers, etc.

check\change the ip addresses that applications are bound to, such as SMTP servers, web servers, etc.

check\change your existing firewall service and NAT rules to accomodate the new ip addresses in use.

This is a non-exhaustive list. You need to check every host\device\service that has an ip address or is bound to an ip address and make sure they are configured for the new ip address range.

share|improve this answer
as joe mentioned this isn't an exhaustive list. Be prepared for something to break temporarily because it's impossible to find all the hard coded IP addresses. SQL applications will typically require a little rework. You should be able to work through the issues as they come up. – PHLiGHT Sep 6 '10 at 17:48

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.