Could the error message be improved to clarify what the issue was? Don't know if it relates to DNS, sockets, ports or a specific file. Seems to occur sometimes. https://unix.stackexchange.com/questions/14160/ssh-tunneling-error-channel-1-open-failed-administratively-prohibited-open My internet is stable, all my online browsing working well. This SSH connection also working well from the shell. Both computers on stable Ethernet connections. j@ubuntu1404:~/aws$ ssh -i "j.pem" -C -D localhost:8080 ubuntu@x.x.x.x Welcome to Ubuntu 16.04.2 LTS (GNU/Linux 4.4.0-1030-aws x86_64) ubuntu@ip-x-x-x-x:~$ channel 12: open failed: administratively prohibited: open failed channel 16: open failed: administratively prohibited: open failed channel 20: open failed: administratively prohibited: open failed channel 5: open failed: administratively prohibited: open failed channel 6: open failed: administratively prohibited: open failed channel 7: open failed: administratively prohibited: open failed channel 3: open failed: administratively prohibited: open failed channel 4: open failed: administratively prohibited: open failed channel 6: open failed: administratively prohibited: open failed This is in a 10 minute period. Assuming these messages are from "ssh" client? SSH ob client and SSHD on server is OpenSSH_7.2p2 Ubuntu-4ubuntu2.2, OpenSSL 1.0.2g 1 Mar 2016
Please upgrade to a newer version, this was fixed in 7.4. https://anongit.mindrot.org/openssh.git/commit/?id=858252fb1d451ebb0969cf9749116c8f0ee42753 Author: dtucker@openbsd.org <dtucker@openbsd.org> Date: Wed Feb 1 02:59:09 2017 +0000 upstream commit Return true reason for port forwarding failures where feasible rather than always "administratively prohibited". bz#2674, ok djm@ Upstream-ID: d901d9887951774e604ca970e1827afaaef9e419 *** This bug has been marked as a duplicate of bug 2674 ***
[...] > Assuming these messages are from "ssh" client? No, they're generated by the server and sent to the client which displays them.
Great! Thank you for fixing this already. Apologies, I'm using latest Ubuntu LTS version, will get new version in six months I believe.
closing resolved bugs as of 8.6p1 release