Exchange Server 2003 supported a utility called WinRoute which allowed an administrator to connect to the Routing Engine Service on port 691, query it, and retrieve a view of the Routing Topology as seen by the server. The Routing Log Viewer in Exchange Server 2007 provides a similar function to WinRoute but for Exchange Server 2007 Hub Transport and Edge Transport roles.
Since there is no Routing Engine to query, the log viewer allows an administrator to open a routing log file which contains information about what the routing topology looks like as seen by the server. To determine what the current routing topology looks like to Exchange Server, utilize the latest log file as indicated by the timestamp on the last modified date.
Furthermore, it allows the administrator to open a second routing log and determine the changes that have occurred within the routing topology between two time periods. This provides a great benefit in instances where routing problems resolve themselves before the issue could be troubleshot or for determining which changes have occurred in the topology over time. In these cases, if problems were due to changes in the routing topology, the utility can be used to compare those changes and hopefully provide clues as to why it occurred.
Note: This tool will ship with Exchange Server 2007 Service Pack 1 and will be available via the Mail flow tools within the Toolbox.