connchk

A tool to check if the connectivity of a system exists between source and destination

What's in the repo

• chkports.py — TCP port checker. Takes hosts as arguments or from a file and ports as a comma-separated list, then prints a color-coded ✔/✘ line per host:port pair with a pass/fail summary. Runs non-interactively when you pass flags, or drops into guided prompts for anything you leave out.
• connchk.py — runner around the same check with a local/remote switch. Remote mode connects over SSH (paramiko), copies chkports.py to /tmp on the target, runs it there, streams the output back, and removes the file afterwards. Also runs non-interactively or with guided prompts.

Both scripts print a title banner (suppress it with --no-banner), exit 0 when every port connected and 1 when any failed (handy for scripting), and accept --no-color for plain output.

Requirements

• Python 3
• colorama (both scripts) and paramiko (connchk.py remote mode):

python -m pip install -r requirements.txt

Usage

Run either script with no arguments for a fully interactive, guided session, or pass flags to run non-interactively. Both accept --help.

Check ports from the local machine

Hosts as command-line arguments:

python3 chkports.py 192.0.2.10 192.0.2.20 --ports 22,80,443

Hosts from a file, one per line (blank lines and # comments are ignored):

python3 chkports.py --file hosts.txt --ports 443 --timeout 1.5

Every host is checked against every port. --timeout sets the per-connection timeout in seconds (default 3). With no --ports (or no hosts), the script prompts you for what's missing.

Run the check locally or on a remote host

Locally:

python3 connchk.py --local 192.0.2.10 192.0.2.20 --ports 22,80,443

On a remote host over SSH:

python3 connchk.py --remote --host 192.0.2.50 --user ops \
  --file hosts.txt --ports 443

connchk.py copies chkports.py to the target and runs the check from there. For non-interactive remote runs, authenticate with an SSH key via --identity ~/.ssh/id_ed25519, or supply a password through the CONNCHK_PASSWORD environment variable. Run connchk.py with no mode flag to be asked whether to go local (l) or remote (r) and prompted for any missing details.

Note: remote mode auto-accepts unknown SSH host keys (AutoAddPolicy). Be careful with this outside of environments you control — don't blindly trust host keys of systems you don't recognize.

License

connchk is licensed under the GNU General Public License v3.

Contributing

See CONTRIBUTING.md for local setup, the validation suite, and the pull request process.

Security

Please report vulnerabilities privately — see SECURITY.md. Never include passwords, SSH keys, or private host details in public issues.