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moving DHCP from one server to another

I am running DHCP on a win 2k3 server and I want to move my DNS and DHCP over to a new windows server 2k8 R2.  I would like to have a split scope, does anyone recomend any good sites that depict the transition clearly?
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2 Solutions
Paul MacDonaldDirector, Information SystemsCommented:
Moving and splitting a scope are two different things.  If you're splitting an existing scope, your best bet is to just come in over a weekend and set up the new scopes.  If you're moving an existing scope, you can do this:

DNS is easy - just set up the new server; make sure everyone can see the new server/is pointed to it; decommission the old one.
afactsAuthor Commented:
here's the problem, I'm having some dhcp server problems, so I didn't want to export the databases, I wanted to create it from scratch, so I don't import the dhcp problem over to my new server.  But perhaps since the data is just a .txt file, the new server might not experience the problem.  I have PCs not able to get IPs from my dhcp server and then I have "bad_address" listed numerous times in my dhcp server.

Can I perform this transfer during business hours? I'm assuming the PCs that have the lease, should continue to be fine until the lease expires, right?

so with DNS, I will create two new DNS servers, but how do I replicate the data from the old server to the new server, I'm not sure how to do that, and now sure how to decommission it?

Also, I'm still planning to use that server for a few more months, as I have other crtical programs running on it.
Paul MacDonaldDirector, Information SystemsCommented:
Clients with a lease will try to renew that lease periodicallly.  It won't hurt them if DHCP is down, but if a lease actually expires while DHCP is down, that client will lose network access.

What you can do is set and configure up the DCHP service, but leave the service turned off.  Then, after hours, kill one DHCP server and bring the other online.

As to DNS, setting up the additional servers is a snap.  If they're all AD integrated, they'll all end up with the same data once they replicate with each other.  Once the two new DNS servers are set, you can kill the service on the old server.
Changing the DHCP scope subnet mask
Change the subnet mask in existing DHCP scope
You can’t change the subnet mask of the DHCP scope directly without deleting the scope, need to delete the DHCP scope first then recreate the scope with new subnet, but this will lead to large amount of manual work
To avoid the manual work use the below netsh command to Change the subnet mask in existing DHCP scope with the simple steps
Use the below command to export the scope configuration
C:\>netsh dhcp server \\”Server name” scope “scope subnet” dump>c:\dhcp.txt
C:\>netsh dhcp server \\Test01 scope dump>c:\dhcp.txt
To change the subnet mask of the scope
Open the dhcp.txt file and change the subnet mask, dhcp.txt file resemble the following

Changed the current scope context to scope.
Dhcp Server add scope "Vlan-1" "Vlan-1"
 Dhcp Server Scope set state 1

Edit the file and save
After this, delete the scope and run the below command to create the scope from the txt file

C:\>netsh exec c:\dhcp.txt
This will automatically create the DHCP scope with the new subnet mask
This way you can change other configuration details along with subnet mask change, like IP range and Excluderanges

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