What is the best way to change the IP address of the DS server?

You should check and change the IP address of the DS server in the following places:

• Change your aclient settings over to point to the new IP address (or the server's hostname if possible)
• Stop the Altiris eXpress Server, PXE Config Helper and PXE Manager services
• Change the IP information within these files in the eXpress share:
  • .\default.cfg
  • .\pxe\pxe.ini
  • .\pxe\pxemanager.ini
  • .\pxe\rpc.ini
• Start the Altiris eXpress Server, PXE Manager and PXE Config Helper services (Note the order of start up)
• Change each PXE / Bootworks configuration to point to the new IP address (lmhosts file)