I have a single Exchange 2003 server within a single Active Directory domain. I plan to install Exchange 2010 and slowly move over to the new server and eventually retire the Exchange 2003 Server. I've read that one of the prerequisites is to suppress Link State routing via a registry edit on the Exchange 2003 server. As I only have a single Exchange 2003 server do I need to suppress the link state updates so I can introduce the Exchange 2010 without creating routing loops? Or will it be ok to leave? Many Thanks Chris