How to Configure a Hub Site
Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-03-19
This topic explains how to use the Exchange Management Shell to configure an Active Directory directory service site as a hub site for message routing in Microsoft Exchange Server 2007. In your Exchange organization, you may want to force relay of all message delivery through a particular Active Directory site. In this scenario, connectivity may prevent direct Simple Mail Transfer Protocol (SMTP) relay between sites and require that messages be relayed through an interim site before they are sent to their destination. You may also want to relay all messages through a particular site because of your organization's internal policies.
You can use Exchange Management Shell tasks to designate an Active Directory site as a hub site. By designating an Active Directory site as a hub site, you cause additional overall overhead because more servers are involved in message delivery. Be aware that routing only recognizes and stops at a hub site if the hub site is somewhere along the least cost routing path. When an Active Directory site is configured as a hub site, routing paths that include that site are always relayed through the hub site.
After the least cost routing path is chosen, routing determines whether there is a hub site along that path. If a hub site is configured, messages stop at a Hub Transport server in the hub site before they are relayed to the target destination. If there is more than one hub site along the least cost routing path, messages stop at each hub site along the path.
You must understand that this variation to direct relay routing is only in effect when the hub site is located along the least cost routing path.
Determine the name of the Active Directory site that you want to configure as a hub site. You can examine the contents of the routing table logs and view the data in the ADTopologyPath ID section to verify that the selected site exists along the least cost routing path between two Active Directory sites.
To perform this procedure, the account you use must be delegated the Exchange following:
Exchange Organization Administrator role
For more information about permissions, delegating roles, and the rights that are required to administer Exchange 2007, see Permission Considerations.
Run the following command:
Set-AdSite -Identity "Site A" -HubSiteEnabled $true
For detailed syntax and parameter information, see Set-AdSite.