Changing the IP address on your SBS is much more than just changing the IP address of the Local Area Network Interface. There are at least EIGHT areas that must be modified and some of those require multiple changes. Luckily, SBS has the Change IP Address Tool! Many enterprise network administrators wish they had this on their servers. Here’s what it does (as quoted from Microsoft’s SBS Training Guide):
Once the user specifies a new IP address by running the Change IP Address Wizard and clicking "OK," the wizard will perform a series of actions to configure the server and appropriate services to use the new IP address.
Note: The tool will need to be able to detect whether the ISA, DHCP, and WINS services are enabled; if any of them are not, then the Wizard will not perform the configuration actions for those services.
The tool will modify the IP address of the local network card to the new IP address and set the subnet mask appropriately. The Default Gateway of the internal network card will not be changed, so if there was a Default Gateway defined, it will still be defined after running the tool. If the Default Gateway is blank, (as it should be in most cases), then it will stay blank. In addition, the DNS and WINS server entries for the server will be changed to point back to the server itself. Therefore, on the external network adapter, the DNS settings will be configured to point to the internal network adapter.
If the new IP address is in the same scope of the old IP address, the tool will simply add a new exclusion to the DHCP scope for the new server IP address. It will also set the following DHCP Scope Options. The tool will check the 003 Router option of the DHCP service, and if the router option is not set to the SBS server itself, it will not modify this option. Otherwise, it will reset the 003 Router option to match the new IP address of the SBS server.
If the new IP address is in a different scope from the old IP address, the tool will create a new scope based off of the new IP address, and follow the same configuration tasks that Server Setup performs.
The tool will update the DNS listeners by adding the new IP address to the list of IP addresses to listen to. It will also delete the reverse lookup zone if the zone no longer matches the new IP address, and create a new reverse lookup zone.
If ISA is installed, the tool will need to construct a new LAT based upon the new IP address, and the outgoing Web requests configuration of ISA to remove the old IP address and add a listener for the new IP address.
If the server has been configured for a dial-up connection, the tool will modify the client address set created by ICW to change the IP address to the new private IP address of the SBS server.
If ISA is not installed, then the tool will check to see if RRAS is being used for firewall. If it is, the tool will update the IP address for inbound filters on the external network card.
If Exchange is installed, and relay restrictions are defined for the SMTP service, the tool will delete the current relay restrictions, and add in a new set using the new IP address and subnet mask defined.
After making all changes, restart the WINS service to make sure changes are picked up.
The tool will update the server.txt file that is in the directory %system root%\Inetpub\ConnectComputer. It will need to modify the value for the server IP address to the new IP address of the server.
The tool will check the IIS permissions on the Default Web Site and its directories. For any directories that have had specific IP permissions set, the tool will modify those permissions to match the new local IP range.
If ISA is running on the server, the tool will run SBSIISConfig to configure IIS appropriately.
When the Change IP Address Tool is run, the tool will maintain a log of actions that it performs. This log file is kept in the directory %sbsprogramdir%\support. The file will be called changeiplog.txt. If the file does not already exist then the tool will create it. If the file does already exist, the tool will not overwrite the file but will instead append the new content to the end of the current file.
At the start of each run, the tool will log:
• Date/time of this run.
• Username of the user running the tool.
• Old IP address and subnet mask.
• New IP address and subnet mask.
• For each action performed by the tool, a success or failure message.
• If a failure occurs, log the error information provided by the service being configured.
• Any additional debugging information required.