When trying to edit a host configuration in the Messaging Gateway Control Center web interface, an error states that the Control Center cannot find a running Agent and will not proceed to the host configuration pages.
The error states:
Cannot find an Agent that is running. Please check the specified host, and that the Agent will allow connections from this IP address.
This error occurs when the Control Center is not able to communicate with the Scanner host's Agent service. This most often occurs after an IP address change; the Agent service has an Access Control List (ACL) of what IPs to communicate with.
This can also occur if there is an environmental network situation that prevents the communication.
To correct this issue, check the network environment to make sure there are no network issues that might be interfering with the Control Center to Scanner communication, such as firewall rules, problematic routes, hardware issues, etc...
Otherwise, or if the Messaging Gateway appliance is a combination server with both the Control Center and Scanner in one, review the Agent configuration to make sure the Control Center is allowed to communicate with the Scanner. Log into the Scanner command line with the default admin account and enter the following commands.
To see the current ACL:
If the IP address of the Control Center is not listed in the Agent's ACL, it can be added with the following (changing "<IP>" to the actual IP of the Control Center):
agent-config --add <IP>
Note: For more information about the agent-config command, reference the following article:
agent-config — configures the agent that connects hosts to the Control Center
Lastly, restart the agent service to ensure it is loading properly:
service agent restart