Linux Commands / IT Support Guides
Collect SSH connection diagnostics without weakening security
An SSH failure can happen during DNS resolution, TCP connection, key exchange or authentication. Verbose output helps identify the stage before any server-side change.
Environment and inputs: Linux · Bash-compatible shell; package and service names vary by distribution
Try the diagnostic command
Use the stated shell and platform. Replace sample domains, addresses, services and paths with values from the system you are authorized to support.
ssh -v support@example.comHow to read the result
The client prints progress messages about connection and authentication attempts. Permission denied indicates a different stage from connection refused, name resolution failure or host-key mismatch.
What to do next
Replace the example account and host with an authorized target. Compare the offered identity with the expected account, and verify host-key changes through a trusted channel.
Before you make a change
Do not disable host-key checking to suppress a warning. Verbose output can expose usernames, hostnames and key filenames even though it should not print private key material.