Package: openssh-server Version: 1:7.5p1-5 Severity: normal We configure sshd (/etc/ssh/sshd_config) with the statement "ListenAddress host", e.g "ListenAddress host1.example.net". In the past this was a pretty robust solution as SSHD check the address only at boot time and the unit did restart the service in case of failure. A temporary DNS problem wasn't something to worry about. Now the unit contain (RestartPreventExitStatus=255) and 255 is not a specific error condition but what sshd reply in case of any error.
We lose the possibility to manage servers with SSH if there are DNS problem or network latencies at boot time. So a temporary error become a permanent failure. sshd[15898]: bad addr or host: host1.example.net (Name or service not known) systemd[1]: ssh.service: Main process exited, code=exited, status=255/n/a systemd[1]: Failed to start OpenBSD Secure Shell server. systemd[1]: ssh.service: Unit entered failed state. systemd[1]: ssh.service: Failed with result 'exit-code'. I think that the change happened to solve https://bugs.debian.org/cgi- bin/bugreport.cgi?bug=778913 I know that I can change the unit in /etc/systemd but I'd prefer to stick to use distribution units to get all the improvement you do on every package release. Thank you very much for all your work. -- System Information: Debian Release: 9.0 APT prefers unstable APT policy: (500, 'unstable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.9.0-3-amd64 (SMP w/4 CPU cores) Locale: LANG=it_IT.UTF-8, LC_CTYPE=it_IT.UTF-8 (charmap=UTF-8), LANGUAGE=it_IT.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages openssh-server depends on: ii adduser 3.115 ii debconf [debconf-2.0] 1.5.61 ii dpkg 1.18.24 ii init-system-helpers 1.48 ii libaudit1 1:2.6.7-2 ii libc6 2.24-11 ii libcomerr2 1.43.4-2 ii libgssapi-krb5-2 1.15-1 ii libkrb5-3 1.15-1 ii libpam-modules 1.1.8-3.6 ii libpam-runtime 1.1.8-3.6 ii libpam0g 1.1.8-3.6 ii libselinux1 2.6-3+b1 ii libssl1.0.2 1.0.2l-2 ii libsystemd0 232-25 ii libwrap0 7.6.q-26 ii lsb-base 9.20161125 ii openssh-client 1:7.5p1-5 ii openssh-sftp-server 1:7.5p1-5 ii procps 2:3.3.12-3 ii ucf 3.0036 ii zlib1g 1:1.2.8.dfsg-5 Versions of packages openssh-server recommends: ii libpam-systemd 232-25 ii ncurses-term 6.0+20161126-1 ii xauth 1:1.0.9-1+b2 Versions of packages openssh-server suggests: pn molly-guard <none> pn monkeysphere <none> pn rssh <none> ii ssh-askpass 1:1.2.4.1-9+b2 ii ssh-askpass-gnome [ssh-askpass] 1:7.4p1-10 pn ufw <none> -- debconf information excluded