DHCP Migration

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31st May 2011, 03:19 PM
techie08

DHCP Migration

Hi

I have just migrated my 2003 DHCP server to 2008R2 and Clients are taking just over a minute to get an IP Address when i do a ipconfig /release /renew

A error will also come up saying "An error occured whiloe renewing interface Local Area Connection : Unable to contact your DHCP server. Request has timed out.

If i then do a ipconfig /all it does get an ip address.

Has anyone had this before??

Clients are XP pro SP3

Thanks Everyone
31st May 2011, 06:55 PM
bart21

What procedure did you use to move dhcp. Have you unauthorised the old dhcp server

Nick
1st June 2011, 08:29 AM
techie08

Hi

I used the 2008 R2 migration tools to migrate DHCP. I havent unauthorised DHCP in the 2003 DC yet though, i just stop the DHCP service. Is this something i definatly need to do???

Thanks
1st June 2011, 09:52 AM
jonny_2010

i posted in wrong thread, sorry
1st June 2011, 09:53 AM
bart21

i would try it, you can always re autherize again if neccessary.

It may be looking for that server first as it is still autherised, then when it times out looking for that server picks an address up from the new one.

nick
1st June 2011, 11:13 AM
techie08

Tried that but its still the same. I Just found out that imacs aren't getting an IP Address at all.
1st June 2011, 11:35 AM
techie08

Ive just deactivated the 2008r2 DHCP scope and reactivated the 2003 one and it assigns an IP really quick, iMacs also now get an IP.
Does anyone have any thoughts?
1st June 2011, 01:06 PM
techie08

I have uninstalled DHCP from 2008 r2 and reinstalled it and created the new scope and it works perfectly. Looks like there was something that went wrong with the migration.
1st June 2011, 01:22 PM
gshaw

Quote:

Originally Posted by techie08

I have uninstalled DHCP from 2008 r2 and reinstalled it and created the new scope and it works perfectly. Looks like there was something that went wrong with the migration.

Doesn't fill me with confidence for when I have to migrate!

Did you use these commands to do it?

http://technet.microsoft.com/en-us/edge/Video/ff710739
1st June 2011, 01:26 PM
techie08

Yes i did, Exactly how it explained.

Not sure if it would of been better to install the DHCP role first then migrate or if was an issue with my 2003 DHCP in the first place that 2008R2 didn't like
1st June 2011, 01:39 PM
gshaw

Did you stop the services on both before the import? In theory it shouldn't make a difference whether the role was installed as it's meant to do it as part of the migration process although I'm paranoid and will probably do it manually when it comes to it.

Btw did you use the IP migration switch as well or did you have a new address for the new DHCP server?
1st June 2011, 01:42 PM
techie08

Quote:

Originally Posted by gshaw

Did you stop the services on both before the import? In theory it shouldn't make a difference whether the role was installed as it's meant to do it as part of the migration process although I'm paranoid and will probably do it manually when it comes to it.

Btw did you use the IP migration switch as well or did you have a new address for the new DHCP server?

No i had a new address for the server. To be honest it may be just as easy to start fresh. When i did, it cleared out the DNS entries and put them back in when it got an ip from the new DHCP server.
1st June 2011, 04:52 PM
Duke5A

I just migrated scopes from a handful of edge domain controllers back to a single server, but they were both 2003 R2 boxes. I used these commands at the command line to do it...

To export the scopes along with the leases:

Quote:

netsh dhcp server export "filename" "scope to export"
ex: netsh dhcp server export Site01.DHCP 10.1.64.0

To import the scopes along with the leases:

Quote:

netsh dhcp server import "filename" "scope to import"
ex: netsh dhcp server import Site01.DHCP 10.1.64.0

I didn't have to down the DHCP server service during the process either. Don't forget to change IP Helper addresses in core switches where needed too.