Error Message: Unable to create listener (Address already in use)

"Unable to create listener" errors are returned when some other service is utilizing the Broker's UDP or TCP ports; this may be a previously started instance of the Broker, or any other process. If you receive "Unable to create listener" errors, take the following action:

1. Access the Multi-Tier server components installation.
   
2. Use ps -ef | grep oplrqb | grep -v grep (Unix) or the Task Manager (Windows) to search for a running Broker process. If you find one, terminate it. You cannot run two Broker instances on one machine.
   
3. If no Brokers are running, run netstat -a | grep 60001 from DOS or a UNIX terminal to check whether another service is using UDP Port 60001. If so, try to reassign that service, or start the Broker before the other service.
   
4. If UDP port 60001 is free, use netstat -a | grep <port-number> to check the status of the Broker's Listen and PortLow TCP ports. These ports both default to 5000. However, you may want to verify your settings. Take the following action:
   
   1. Use a text editor to open your oplrqb.ini file. You will find this file in the /bin sub-directory of your Multi-Tier server components installation.
      
   2. Locate the [Protocol TCP] section.
      
   3. Note the values set for PortLow and Listen.
      
   4. Search for these port numbers in your netstat output.

Related Documentation

• Firewall Considerations for Multi-Tier "Enterprise" Edition Data Access Drivers
  
• Configuring Server-side Firewalls for Multi-Tier Connectivity
  
• Error Message: Unable to contact the OpenLink License Manager
  
• OpenLink License Manager Networking Considerations
  
• Configure Multi-Tier Request Broker for Use on Machines with Multiple Network Cards