If the System Agent could not communicate with CA (dSeries) Workload Automation Server, you can issue 'listagent' command from the Command Line Interface (CLI) on the Desktop Client to check the Agent status or check the content of 'status' and 'status.os' files (located in the Agent installation directory). The latter would provide additional information about the Agent, including the last Agent start information.
In order to diagnose the problem, you can check the following;
- Do you have any communication/network problem?
- Did Manager connection parameters change in the agentparm.txt file (located in Agent installation directory)?
- Did Agent connection parameters change in the server Topology in Admin perspective on the Desktop Client?
- Did Manager and/or Agent IP addresses change?
- Did Agent not start properly?
- Is there Firewall between CA (dSeries) Server and Agent
- Did the Firewall rules change?