Restrict authorized_keys safely
A public key needs narrower permissions such as a forced command, source restriction, or disabled forwarding without breaking its intended automation.
SSH config file not applied
The effective hostname, user, port, key, or proxy differs from what the operator believes the config declares.
SSH preauth connection closed
The server logs a disconnect before authentication finishes; this may be normal client abandonment or a clue to method, policy, or resource failure.
SSH SOCKS proxy not working
The -D listener exists or should exist, but applications do not route DNS and TCP traffic through the dynamic SOCKS proxy as intended.
SSH host key changed warning
The host now presents a key that differs from the key saved for that hostname or address.
SSH could not resolve hostname
The client cannot turn the supplied SSH host name into an address, or an alias is being resolved by DNS instead of SSH config.
SSH MaxSessions limit reached
One authenticated transport cannot open another shell, command, subsystem, or forwarded session because its channel limit is exhausted.
SFTP chroot ownership error
An internal-sftp account authenticates but sshd refuses the chroot because a path component is writable or owned by an unsafe identity.
SSH terminal type error
SSH connects, but a remote command such as clear, top, or an editor does not recognize the local TERM value.
Set up an SSH user CA
The operator wants short-lived signed user access without copying every user's public key to every server.