Preventing "real server connect failed" errors for MAPI
Occasionally, the following error may appear when a Virtual Service is using a wildcard:
kernel: L7: Real Server Connect failed (client:port->virtual service:wildcard port->real server:port)L7: Real Server Connect failed (client:port->virtual service:wildcard port->real server:port)
The LoadMaster forwards the traffic on a random port and the Real Server will reject it because the port is closed.
To fix this issue, add two static ports for the Offline Address Book (OAB) and Remote Procedure Call (RPC) on the Exchange 2010 Real Servers.
To do this, follow the steps below in the LoadMaster Web User Interface (WUI):
- In the main menu, select Virtual Services > View/Modify Services.
- Delete the Virtual Service that is using the wildcard port.
- Re-create the Virtual Service using port 135.
- In the Virtual Service modify screen, expand the Standard Options section.
- Enter the extra ports in the Extra Ports text box. Separate the ports by commas.
When you click the View/Modify Services option in the main menu, you should see something similar to the screenshot below, for example; 192.168.10.15:135(+2)
Refer to the following Microsoft article for further details: Configure Static RPC Ports on an Exchange 2010 Client Access Server.