Good Morning, I am trying to understand the role of job launcher (e.g. ssh ) in MPICH. I have looked over the mpich design documents and hydra process management doc. But did not get the answer I am looking for. Would you please give the answer of my following question? 1. If hydra uses ssh as a job launcher for multiple machines, then are all communications done by hydra performed using ssh tunnel? In other words, if I configure ssh in port 22, then will all communication done by hydra with other machines use port 22? Thank you. Best Regards, Abu Naser _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss