An agent's status is shown as offline and will not come online even though the agent process, cybAgent, is running and sendevent -E MACH_ONLINE events were sent to place it online. Messages similar to the following appear in the $AUTOUSER/out/event_demon.$AUTOSERV file
[09/12/2014 11:17:01] CAUAJM_W_40258 Machine <host123> has explicitly rejected communications. Taking offline.
[09/12/2014 11:17:02] <Machine <host123> forced offline due to invalid agent configuration.>
Workload Automation AE 11.3.x
Platform - Any
Database - Any
When an "explicitly rejected communications" event occurs all communication between the scheduler and that agent is suspended. No further communication will be attempted. Only a manual sendevent -E MACH_ONLINE event will potentially bring the machine back ONLINE with the scheduler. This is by design so the scheduler does not waste time trying to communicate with inconsistently configured machines.
The "invalid agent configuration" message suggest that the agentname in the agentparm.txt file does not match the agent_name in the jil machine definition. These must match otherwise the agent will ignore the incoming messages.
If the agent names did not match one would also see the following in the agent's receiver.log: Can't parse the message: cybermation.library.communications.CybConversationWrongMessageException: Wrong target
If the encryption is inconsistent between the agent's cryptkey.txt and the jil definition the machine will go to an Unqualified state and the receiver.log will contain "bad padding" messages.
If the port number is inconsistent then the machine will go to an Unqualified and then Missing state and nothing will be seen in the receiver.log as the scheduler's messages would be going to the wrong port.
NOTE - Any changes to the agentparm.txt file would require a restart of the agent.
For more details about machines please refer to the documentation.