Description of problem: The exact same sshd config (with PermitTunnel yes) works with openssh-7.6p1-7.fc29.x86_64.rpm and doesn't with openssh-7.7p1-2.fc29.x86_64 With two preconfigured tun0 interfaces on both sides and logging in as root: # ssh <7.7 host> -w 0:0 ... channel 0: open failed: connect failed: open failed ... The client version is the same openssh-7.6p1-5.fc27.x86_64
Thanks for the report. Already discussed upstream [1] and fixed in 7.7 branch upstream. I will bring the fixes in soon to Fedora. [1] https://bugzilla.mindrot.org/show_bug.cgi?id=2855
openssh-7.7p1-3.fc28 has been submitted as an update to Fedora 28. https://bodhi.fedoraproject.org/updates/FEDORA-2018-9458d7b545
openssh-7.7p1-3.fc28 has been pushed to the Fedora 28 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-9458d7b545
openssh-7.7p1-3.fc28 has been pushed to the Fedora 28 stable repository. If problems still persist, please make note of it in this bug report.