Chapter 9 · Guide · 1B Terminal
Common problems and solutions
When something fails, the app tells you what happened and what to check; tap Details to see the technical message. These are the most common cases.
Problems and solutions
“Can't find the server …”
The name doesn't resolve. Check the address for typos and that the phone has Internet. If it's a name on your VPN or home network, connect to that VPN or network first.
“… refused the connection on port …”
The server is reachable but nothing is listening on that port. Check the port in the host (22 by default) and that the SSH server is running (sudo systemctl status ssh or sshd).
“… didn't respond in time” or “Can't reach …”
The server may be off, or a firewall, a VPN or your network is blocking it. If the server is only reachable at home, add its other address (VPN, Tailscale…) in Advanced › Other addresses.
“The server rejected the login” or “The server rejected the key”
Check the Username. With a key, make sure its public key (tap it in Keychain) is in ~/.ssh/authorized_keys of that user, and that the file isn't writable by others (chmod 600 ~/.ssh/authorized_keys, chmod 700 ~/.ssh).
“The server fingerprint has changed!”
If you've reinstalled the server or changed its keys, check the new fingerprint on the server and use Forget saved fingerprint…. If you weren't expecting it, don't connect: someone could be intercepting the connection.
“No common security algorithms”
The server only offers outdated algorithms. If it's an old server or a network device you trust, turn on Allow legacy algorithms in Advanced for that host only.
Alerts don't arrive
Check that notifications are allowed for 1B Terminal in Android, that Notify when a session needs you is on, and that the agent sends alerts (Set up the server for agents). You won't get alerts from the session you're looking at. If the phone's battery saver closes apps, exclude 1B Terminal.
“tmux isn't installed on the server…”
Install tmux on the server (sudo apt install tmux or sudo dnf install tmux) and reconnect. Meanwhile you get a normal shell.
“The server doesn't offer SFTP…”
The SSH server has no SFTP subsystem. Ask its administrator to enable Subsystem sftp in /etc/ssh/sshd_config.
“The server didn't allow forwarding port …”
Port forwarding is turned off on the server (AllowTcpForwarding). Without access to its configuration, it can't be done.
Gboard's microphone doesn't appear
Tap the terminal to bring up the keyboard; if it's a different keyboard, switch to Gboard. Gboard shows its microphone in the terminal and in the writing bar.
The session disconnects when I lock the phone
It shouldn't: sessions keep running in the background with a notification. Some phones close apps to save battery: exclude 1B Terminal from battery optimisation. With tmux and Reconnect automatically, you'll get back to the same place anyway.
Written for 1B Terminal 1.2 with real screenshots of the app and example data.