IP Address Range Change!

[jdukarm]

I have inherited a external range 100.100.100.x for an internal network which is causing a few issues. I want to change the IP address range for all PC's on the network to a private range 192.168.0.0 etc.

I know about setting up a new scope on the DHCP server and changing all the IP's etc. The only thing I am unsure of is the DNS settings.

The DNS server is AD integrated and I need to change the IP Range. How do I do this? DNS and AD are obviously well linked and I dont want to reduce the stability of the network. There are other member servers that I can install a new DNS server on so I can uninstall the DC DNS Server, but because its AD integrated will it cause issues? Any ideas gratefully received.

Thanks in advance.

John

 

[mrmoneymatters]

I am getting ready to go through the same thing. The only difference is I am running static and going to dhcp while changing the ip scheme a little. If you are going to set up a new scope make sure you add the new ip scheme to your server nics as well. Your server nics can have multiple ip addresses at the same time. At this point your computers will be able to talk to the server. I think you will have to add the new subnet in ad sites, add it to your existing site. I don't think you have to change anything on your dns zone settings. The zone should be for your domain, it doesn't care what ips are in there.

 

[jdukarm]

Thanks for your response. What about the IP records that are already in the DNS zone?

So if I put the 192.168.0.x address in the server list addresses I dont have to change it?

I would like to put it as a primary ip instead of secondary can I swap them over? Then once the conversion is finished, I can remove the other IP completely?

So as I reregister using DHCP a different set of IP addresses they will just register themselves in the DNS zone?

Thanks for your help this is really useful.

 

[wdoellefeld]

So if I put the 192.168.0.x address in the server list addresses I dont have to change it?

Meaning, can you dual IP the server? If so yes you can.

I would like to put it as a primary ip instead of secondary can I swap them over? Then once the conversion is finished, I can remove the other IP completely?

Yes, but I would leave the old IP there for a week or so.

So as I reregister using DHCP a different set of IP addresses they will just register themselves in the DNS zone?

Yes. After the conversion to the new IP scheme you can either wait or somehow renew the IPs on all the machines.

After all is said and done, run a scan on the old subnet to see if anyone is still holding an old IP and clean them up. Once the old IP scheme is cleaned up you can delete the old DNS records if you want.

 

[jdukarm]

So this seems fairly straight forward is there anything else I should consider when it comes to this?

 

[wdoellefeld]

No idea what your setup is, but make sure if you have any static routes setup on your routers or firewall that will need to change as well. Another good reason for dual IPing the servers and taking the other IPs off slowly one at a time. Having a dual IP saved my butt once because I missed changing a static route.

If you like to remote manage don't forget your other network equipment as well.

 

[jdukarm]

Thanks for all your help. Take a deep breath and here we go!