After a recent successfull login to an openssh-server, if you use ssh-copy-id command with multiplexing enabled ssh client, it hangs indefinitely, and Ctrl-C can't terminate the command. Ssh client's .ssh/config file is set as: Host * ControlMaster auto ControlPath ~/.ssh/sockets/%r@%h-%p ControlPersist 30 Furthermore, if you try to login same server within the above timeout duration, you can successfully login without password. But weirdly, no authorized_keys file is created on the remote server. Our ssh client is openssh-clients-6.6.1p1-25.el7_2.x86_64 on Centos 7.2. Ssh servers which we successfully login to without passwords are openssh-server-7.4p1-11.el7.x86_64 (Centos 7.4), openssh-server-7.4p1-16.el7.x86_64 (Centos 7.5), openssh-server-5.3p1-123.el6_9.x86_64 (Centos 6.10). Ssh-servers are at default settings set by distribution installers.
Sorry about not replying to this earlier. This seems to be a duplicate of bug #2488 (fixed) Assuming that's the case, I'll close this bug now, but please feel free to reopen it, or submit a new one if it turns out that it was not fixed by that change. Cheers, Phil. *** This bug has been marked as a duplicate of bug 2488 ***
close bugs that were resolved in OpenSSH 8.5 release cycle