Migrating DHCP Servers

[markus97]

Hello,

I have an example here. We have 3 dhcp servers running dhcp for 3 different subnets.

We would like to migrate 3 of the server scops on to the 3rd server and have dhcp run on just the 1 server for all 3 subnets.

Is there a migation process for this particular task? Or do we just create the scopes for the additional 2 subnets on the 1 server and thats it?

Any help would be appreciated, thanks.

 

[58sniper]

I've never tried that before (migrating several to one), but when I need to migrate one to another, I always use:

How to move a DHCP database from a computer that is running Windows NT Server 4.0, Windows 2000, or Windows Server 2003 to a computer that is running Windows Server 2003

http://support.microsoft.com/kb/325473

Ignore the top section and start at Export the DHCP database from a server that is running Microsoft Windows Server 2003

I suspect that you could export from three and import on one. You could certainly test it.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[JimWells]

Rather than migrate the databases - as long as the DHCP server can ping any DHCP client on those scope subnets -- just slowly bring the lease time down on the old servers, then create the scope on the new one, update any network broadcast addresses/routing.

There is an option on the DHCP server level - DHCP server properties, Advanced tab, - 'conflict detection attempts'. This amounts to a ping from the DHCP server of the lease IP address, before it is handed back to the requesting client. That way, the new server doesn't need the database to know about existing leases - if the clients with an exsiting lease/IP are online, the ping will succeed and a different IP will be handed out with the lease.

I've not tried to merge DHCP databases like you are proposing - and even if you have a large number of scopes, there are VBScipt examples on using WMI to create them on the new server....