Routing Engine is stopped

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool queries the Win32_Service Microsoft Windows® Management Instrumentation (WMI) class to determine whether the Microsoft Exchange Routing Engine service (RESvc) and the Simple Mail Transfer Protocol (SMTP) service (SMTPSVC) are running. The Exchange Server Analyzer displays an error if the Exchange Server Analyzer finds that either of the following conditions is true:

  • SMTPSVC is running.

  • RESvc is not running.

If RESvc is not running on all Exchange servers that relay messages, routing problems may occur. An Exchange Server configuration that relays messages without RESvc running is not a supported configuration.

Like Exchange 2000 Server, Exchange Server 2003 uses a link state routing algorithm and a routing protocol to propagate link state information in the form of a link state table. The link state table is stored in memory on all Exchange 2000 Server and Exchange Server 2003 servers in the organization.

A link state algorithm provides the following advantages:

  • Each Exchange server can select the optimum message route at the source instead of sending messages along a route where a link is unavailable.

  • Messages no longer bounce back and forth between servers because each Exchange server has current information about whether alternative routes or redundant routes are available.

  • Message looping no longer occurs. Message looping was sometimes a problem in earlier versions of Exchange Server.

Exchange Server collects the following information from the link state table:

  • The link state table documents the routing topology of the whole Exchange organization.

  • The link state table documents the availability of each connector in the topology. An available topology is "up." An unavailable topology is "down."

  • The link state table documents the costs and the address spaces that are associated with each available connector.

Exchange Server uses this information to determine the route with the lowest cost for the destination address. If a connector along the route with the lowest cost is unavailable, Exchange Server determines the best alternative route on the basis of costs and connector availability. RESvc is required for link state routing.

To correct this error, you must configure RESvc to start automatically. You also must make sure that RESvc is running during production hours.

To correct this error

  1. Click Start, point to Programs, point to Administrative Tools, and then click Services.

  2. In the list of services, right-click Microsoft Exchange Routing Engine, and then click Properties.

  3. On the General tab, on the Startup type menu, select Automatic, and then click OK.

  4. Right-click Microsoft Exchange Routing Engine, and then click Start.

For more information about routing messages in Exchange Server 2003, see the Exchange Server 2003 Transport and Routing Guide (