My jenkins-controller is connected to the agents which exist on a different network, there is a gateway between the controller and the agents, I have configured a backup gateway which kicks in if the primary gateway fails, when I do such a failover the secondary or standby gateway comes up and agent and controller can ping each other but the controller can not run build/jobs on the agents on some of the agents. The agent and controller are connected via the SSH, I don’t know if the controller fails to reestablished the SSH connection for some of the agents via the secondary gateway which should not occur as I can ping the agents from the controller.
From the controller, perform SSH connection (using terminal) with failover gateway and see how it go. Perhap enable some debug flag on your ssh command could help Identify the issue
That works without any problems ! It is actually the Script Console in the jenkins controller that can’t run anything on the agent and it gives the Error 504 Gateway Time-out.