Understanding the OrgInfo Packet

The OrgInfo packet is the link state table that contains the details and status of the Exchange organization's routing topology. Routing group masters propagate this information throughout the organization in the form of the OrgInfo packet. The packet includes details such as organization name, routing groups, connectors, and address spaces. The WinRoute tool displays the contents of the OrgInfo packet in a more readable form than the raw packet. To identify in detail the various portions of this packet, however, this topic discusses the packet in its raw data form.

In general, information fields within the packet are separated by parentheses in the following way:

(Routing group (Routing group members (Connectors in routing group (Connector config))))

Within the packet, GUIDs are referenced for the various components. Certain information is represented in ASCII text, such as:

• Portions of the X.400 and X.500 routing group addresses that are listed in each routing group section.

• The legacy distinguished names, legacyExchangeDNs, of connectors.

• Virtual server FQDNs when listing the source or remote bridgehead servers of connectors.

• For each restriction set on a connector, the distinguished name of the restricted object. For example, if a connector denies usage to three users, the three distinguished names of the users are listed in ASCII text in the packet.

Because the components above are listed in ASCII text, the number of these components in a routing topology affect the overall size of the OrgInfo packet. A practice of denying connector access to users instead of distribution groups or specifying source and destination bridgehead servers when not necessary, for example, will lead to a much larger OrgInfo packet than normal. Because this packet is distributed throughout the Exchange organization, and these restrictions add to the size of the package, the exchange of the link state packet between servers can have profound effects on network utilization depending on the size of the Exchange organization. As a best practice, if you must restrict connector access, use distribution groups rather than users, and only apply specific source and destination bridgehead servers where appropriate if the size of the OrgInfo packet is of a concern.

Another important fact about the size of the OrgInfo packet is that, once a routing group has been created, the routing group remains in memory on each Exchange server in the organization (given that the information has propagated throughout) indefinitely unless all Exchange servers in the organization are shut down simultaneously. This is true even if the routing group has been deleted in Exchange System Manager.