Do I absolutely have to run DHCP on SBS 2008?

When running the Configure E-Mail and Internet Connection wizard in SBS 2003, you had the option to run DHCP services on the SBS server, or leave it on the router within the network.  There was no guidance one way or another, it was a choice you had to make to complete the wizard.
With SBS 2008, we provide guidance.
The guidance is that you should run DHCP on the server.  Why?

1. Microsoft builds, and has been building a really high quality DHCP server built into Windows Server since Windows NT 4.  Why not get one of the highest quality DHCP servers on the market for your network?
2. The SBS team can ensure your DHCP server is set up correctly on SBS, making sure there are no duplicate IP addresses, and that the exclusion range is set up correctly for the server’s IP address
3. If you feel comfortable in the DHCP management UI, you can set up reservations to make sure the same clients get the same IP address.  This is handy for printers, or other things on your network that may act like servers, but you don’t want to manage the static IP address
4. If you’re logging in remotely, you can see which clients are online by which ones have IP addresses in the DHCP management console.  You can also see the clients IP address right in the console, so it makes it easy to find clients on the network, especially if you are remote.
5. DHCP uses limited resources and has essentially no impact on the server’s performance

If the above 5 reasons aren’t good enough for you, and you absolutely must run the DHCP service on the router, here is how you do it.

1. Close the Windows SBS Console, and cancel the Connect to the Internet Wizard if it’s running
2. Click Start and go to All Programs and expand Windows Small Business Server
3. Click on Windows SBS Console (Advanced Mode)
4. On the Network tab, select the Connectivity sub-tab
5. Click on Start DHCP ().
   1. At this point, the DHCP services will be forced to start.  Since you have another DHCP server running on the network, the DHCP service will stop itself, and log an event in the Event Log about how it can’t start because there is another non-authorized DHCP server on the network.  This is ok.
6. Immediately click the same button, this time called Disable DHCP ( ).

Now the networking components of the server will ignore the fact that the DHCP service is not running, keep it disabled, and let you proceed with the Connect to the Internet Wizard without having to disable the DHCP services.
IMPORTANT: Please do not call Microsoft support with an incorrectly configured LAN DNS.  Make sure you make the SBS’s Internal IP address the primary DNS in your 3rd party DHCP server configuration.
Finally, the server is still going to alert you that DHCP services aren’t running, so to fix this:

1. Flip on over to the Computers sub-tab on the Network tab.
2. On the right, click on View Notification Settings.
3. Uncheck the DHCP Server notification, and click OK.

 

Now DHCP services is no longer running on the server, and SBS will be fine with that.  As a final note, please only do this if you have no other way around it, and if you’re familiar with your router UI to set it up correctly.  If not, just disable DHCP on your router, and we’ll take care of the rest!

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