Server 2003 > 2008 R2 Migration

[cscc]

We currently have 1 main DC (running DHCP) and 2 backup DC’s running DNS, all on server 2003.

 

We are looking to move everything over to 2008 R2.

 

I was going to build a 2008 server, add it to the domain, promote it to a DC and transfer the FSMO roles from our old main DC. I was then going to demote all the old DC’s and remove their roles and add DHCP to the new server as a role. I was then going to add 2 more 2008R2 servers as backup DC’s and make them DNS servers.

 

Is this the best way/order to go about things? Or will creating new DHCP/DNS servers play havoc across the network, bearing in mind the settings will be matched to how they were before (scope/reservations etc.)

 

Many thanks

[AngryTechnician]

This is roughly the way I did it. I actually ended up with the new DCs and DNS servers having the same IPs as the old ones, by changing the IP addresses once I had decommissioned the old servers. Didn't really encounter any major problems.

 

The only complication you might need to consider is if one of your existing servers is running an internal Certificate Authority, as transferring an existing CA from one server to another is not as simple as it sounds.

[cscc]

Thank you for the quick response, glad to know its been done in a similar way before! We don't have an internal CA here so I don't need to worry about that thankfully! I shall give it a try!

[Michael]

That's the way to do it I agree, but does your main DC run DNS also? The more servers you have running DNS and DHCP (recommended) the better as it adds redundancy. Just make sure to enable conflict detection (change to 1 or 2) on each DHCP server instance to avoid IP conflicts.

[cscc]

The current main DC is just running DHCP. Thank you, I shall give this method a try.

[soveryapt]

Just a note from when I did a similar thing, if any of your devices point to a DNS name instead of an IP address (so \\servername not \\x.x.x.x etc) make sure you put a CNAME or A Record in your DNS to resolve these to the new servers. Eventually things should propagate through, but it's just one thing I hit that was resolved with that easy step.

 

As for the rest, like others have said, yeah, seems the best way forward, and add as much redundancy as you can, but that goes for all IT deployments really.

[soveryapt]

That's the way to do it I agree, but does your main DC run DNS also? The more servers you have running DNS and DHCP (recommended) the better as it adds redundancy. Just make sure to enable conflict detection (change to 1 or 2) on each DHCP server instance to avoid IP conflicts.

 

And this post proves you learn something new everyday. I've always run a split scope, didn't even look into being able to do this! Ta @Michael for a hopefully very useful pointer.

[Michael]

You're most welcome, happy to help

 

To enable DHCP conflict detection (per server), open up DHCP Server, right click IPv4 > Properties > Advanced (tab). Change to 1 or 2 depending on the number of DHCP Servers.

[soveryapt]

You're most welcome, happy to help

 

To enable DHCP conflict detection (per server), open up DHCP Server, right click IPv4 > Properties > Advanced (tab). Change to 1 or 2 depending on the number of DHCP Servers.

 

Well, that was painless. All set up and working in tandem today. Lovely. I even decided to put back on the second DNS server. I feel good today and have redundancy back again.

[Michael]

Excellent stuff