Folks,

The time has come to move away from SBS 2003 to Windows Server 2012 R2 Standard and need some assistance please.

I am gradually moving services off SBS 2003 onto other servers I have in the estate in order to minimise any impact that may happen when SBS 2003 finally gets turned off after migrating.

The question I have is regarding internet access for the clients. Current setup is that the SBS 2003 is dual NIC (LAN and WAN) with the External Gateway on the WAN pointing to the Router IP Address.

As ISA isn't on Server 2012, then I was thinking of moving the clients directly to the router now rather than having something else to worry about when the migration happens. 

My understanding is that I simply change the Default Gateway on the client PC's away from the Server IP Address and to the Router IP Address.

However, the router IP address is a different subnet (Subnet set in External NIC) to my internal network subnet.  So, do I need to change the LAN IP Address on the router to my internal network and then instead of the cable plugging into my WAN NIC on the Server, plug it directly into the switch??

Hope the above makes sense and wondering if there's anybody else who's taken the same approach and are able to assist.

Kevin

You need to remove ISA before any migration.  I used this excellent post:

http://blogs.msmvps.com/kwsupport/2008/09/07/uninstalling-isa-2004/

Note you will lose ISA's monitoring and reporting features but usually these can be done from your firewall (which you will need).

Yep:  But iirc there is a long ago quirk in that post having to do with which nic you disable - it suggests the LAN one, then change the IP of the remaining one.  Not really necessary as you can disable the WAN nic, change the IP on the LAN side of the router and plug every remaining patch cord into the switch, the LAN side of the router as well.

Many thanks Larry and AMBW. I've read the document that you posted in your link and Larry's comments.  So I can understand correctly:

I cannot simply do what you propose on it's own which is: Disable WAN NIC, change IP on LAN side of router, move patch cord from WAN NIC on server to LAN switch. Then change every client's default gateway to the Router LAN IP Address via DHCP Scope Options.

Do I also need to unistall ISA from the server and the Firewall Client from each workstation as proposed in AMBW's post?

I know when the migration to Server 2012 happens then the workstation uninstall will have to be carried out at some point but trying to avoid making too many changes on SBS 2003 as it's in a bit of a "fragile" state when I joined the company a couple of months ago!