Domain Controller, DHCP, and DNS migration

If you can afford downtime, you can do a 2008r2 to 2012r2 in-place upgrade with your installation media.  The process usually takes about 2-2.5 hours, including post operations testing.

This would maintain ip address and DNS functionality, causing the least amount of disturbance (minus downtime) in your environment.  It's usually the way I like to go.

I'd definitely recommend making a clone of your domain controller (off the network!) and testing the in-place upgrade.

Thanks for all your comments.

The plan is to replace the old physical server and move these roles to a new physical or VM Server.

What I was trying to avoid is having to change any network devices that are statically pointing to the old DNS server.

I was looking for your advice and recommendation in this matter.

Regards,

Serge

If you can afford downtime, you can do a 2008r2 to 2012r2 in-place upgrade with your installation media

Althought this is possible i would not recommend doing an in-place upgrade. As you can always run into issues while doing these and also it does require down time. Whenever i have done this type of migration i always spin up the new server and the migrate the services over.

Are there any repercussions for changing the IP address of a server hosting DC, DNS, and DHCP?

You can use the same IP but what I would recommend is the following...
- bring up the new server 2012R2 (promote as a DC/GC with NEW IP)
- point your DHCP clients to the new IP as a secondary DNS IP (also static addresses as well on servers)
- Ensure replicaiton is working properly
- Demote your 2008R2 DC
- Change the IP Address of the 2008R2 server to a new IP
- Update your VLANs with the DHCP helper address of the new IP you gave to 2008R2

***The above step is only required if you have multiple VLANs and your DHCP server is on a different VLAN than your workstations, or any other devices trying to get a DHCP address***

- Make sure you keep the old 2008R2 IP in the dhcp helper address because it will be used once you trasnfer the DHCP role to 2012R2 DC
- Add the old 2008R2 IP as an additional IP to the 2012R2 DC (now you have 2 IP on the same NIC)
- Ensure replicaiton is working after demotion
- Uninstall DNS from the 2008R2 server that was demoted (this does not happen automatically)
- Change the dhcp scope for DNS to point to the Original 2008R2 DC IP (which is now on 2012R2 DC)
- Remove the Original 2012R2 IP from DHCP scope for DNS
- Migrate the DHCP to the 2012R2 DC
- Remove the 2008R2 machine from the domain (if not longer being used)
- Rmeove the original IP for the 2012R2 DC server, leaving only the Origainl IP address, which is now transferred

Also i would highly recommend making sure that you have atleast 1 other domain controller in the mix to ensure that you have high availability for your DC/GC/DNS.

Aside from that, you should be fine.

Will.

WOW all that and answer was accepted before i posted!

Will.

Hi Will,

I guess, I got ahead of myself. Your recommendation is exactly the answer I was looking for.  The next time, I won't be so darn quick to give points out. ; )

I am just thinking ahead of a DC migration project coming up my way soon.  I will look for you next time I post something related to this subject.

Best Regards,

Serge.