How can you NLB the Hub role ?

By default Exchange hub server create 2 recieve connectors
– Client (ServerName)
– Default (ServerName)

The Default connector is used for all messages that will pass through the hub server. This could be internal or exteranl traffic.

Let take a look at the default settings on the General and Network tab:

The General Tab displays

A. Logging level
B. Maximum Message Size (10mb default)
C. connector name

The Network Tab

A. which is important listens on all IPs by deafult
B. Accepts connections from all Ip’s

Since we want to create an additonal connector that uses port 25 we will need to specify an IP address.

If you need to create an NLB for your hub servers which is an unsupported configuration you can perform the following.

We must create the NLB first so we can associate the NLB IP the hub server before we can create the new connector

Create the NLB on an IP that is not currently used by the server or any connector

1. Launch NLBMGR
2. Click Cluster –> New

3. Enter the IP of the cluster (this will be your NLB address for you Hub server)

4. Configure the ports to load balance (for this demo I used only 25)

5. Add the Hub server to the NLB

6. Complete the wizard.

Now we must specify the non NLB address on the default connector

1. On the default recieve connector
2. Select the network tab
3. Click edit –> specify IP

4. Add the Ip of the server

5. Click Ok

Now its time to create a new recieve connector
– this can be done from the Shell or Gui — new-recieveconnector commandlet

I will use the gui in the example:

1. Select New-recieve connector

2. Name the connector and select the usage –> Next

** for this example I will just use Internet **

3. Edit the local network settings and specify the NLB IP and specify the name for the Helo response on the connector

4. Click New

5. Click Finish

Associate a certificate with the connector
** A self signed cert is used in this example however should not be used in production**

– get-exchangecertifcate will get the current installed certificates
– new-exchangecertificate to generate a self signed certificate
– enable-exchangecertificate to associate SMTP service with the certificate

6. Restart the hub transport just to verify changes take affect.