ssh-connection-test

name	ssh-connection-test
description	Test SSH connectivity to hosts configured in ~/.ssh/config using sshm. Use when diagnosing connection issues, verifying hosts are reachable, or checking all hosts after a network change. Triggers include "test ssh", "ssh connectivity", "can I connect", "ssh reachable", "sshm test".

ssh-connection-test

Guide to testing SSH connections with sshm test.

Test a Single Host

sshm test web

Output:

  testing web ([e-mail]:22)...

  ok  connected  (231ms)

Test All Hosts

sshm test --all

Shows a table of all hosts with connection results and timing.

Connection Result Types

Result	Meaning
connected	SSH handshake succeeded
timeout	No response within 5 seconds
refused	Port is closed
host not found	DNS resolution failed
auth failed	Host reachable but key rejected
unknown error	Other SSH error

Diagnosing Failures

timeout - Host may be down, firewall blocking port, or wrong IP. Check: ping hostname, telnet hostname 22.

refused - SSH service not running on that port. Check if port in config matches actual SSH port.

host not found - DNS issue. Try using IP address directly: sshm edit myhost --host 1.2.3.4.

auth failed - Key not accepted. Check: key exists at IdentityFile path, key is in server's authorized_keys.

How the Test Works

The test spawns ssh with:

• ConnectTimeout=5 to avoid hanging
• BatchMode=yes to prevent interactive prompts
• The host's configured user, hostname, and port
• Runs true as the command (exits immediately on success)

The test does not create a persistent connection and does not execute any shell commands that could affect the server.

Notes

• Connection test uses the host's current config (User, HostName, Port, IdentityFile)
• Test respects IdentityFile if set
• Auth failures are distinguished from unreachable hosts
• Timing shown in milliseconds