Exchange2007: HUB Site

In the HUB-SPOKE network, it is a fully-routed network, which means each server can communicate directly with any other servers without a server in between. DC A can communicate directly with DC B, D, and C. Exchange 2007, by default, uses the direct point-to-point communication. What does it mean? After ADLink, CDLink, and BDLink are created, test the exchange communication. With the Transport service stopped at Site D, you can send messages from Site A to Site B and C.


Implementing the HUB-SPOKE communication --force all message delivery to be relayed through the SITE D.


Open Exchange Management Shell on "DC D", run the following:


Set-AdSite -Identity "Site D" -HubSiteEnabled $true

With the Transport service stopped on Site D, you send messages from Site A to B and D. You will find that the messages are queued at Site A.

Why would you choose to implement the HUB SITE, which incurs more servers in message delivery?

Possible reason: company's internal policy

or connectivity may prevent direct SMTP relay between sites. I does not see that yet.

In the following configuration, a message sent to Tom@SiteD will first stop at Hub Site and then be relayed to Site D. However, the message sent to Joe@SiteC will be directly delivered to Site C because it has the least cost path.

If you increase the cost between Site A and B to 100, the Hub Site will never be used. An Active Directory site is never used as a hub site if it is not on the least cost routing path between two other sites.