When an ssh agent is launched it will compare the MD5 hash of the remoting jar in Jenkins home with the hash of the remoting.jar in the remote root directory of the agent.
- If the file does not exist or is different, it is copied from the Jenkins master.
- If the file is the same, it is ignored.
NOTE: this change NOT guarantee that you can run several agents in the same host sharing the working directory, this behavior is not supported and NOT recommended.
See these two links to see potential issues