PORT 22 / TCPSecurity & RemoteExposure Risk: Medium

Port 22: SSH / SFTP — Secure Shell, SCP, SFTP, and Port Forwarding

Standard port for encrypted remote administration, Git over SSH, and SFTP file transfers. Harden with key-based authentication and fail2ban.

Default Service

SSH / SFTP

Process: sshd

Transport Protocol

TCP

IANA Registered Port 22

Docker Port Flag

-p 2222:22

Container to Host Mapping

How to Check & Kill Process on Port 22 (EADDRINUSE Fix)

macOS & Linux (lsof / kill)

# Find process using port 22
sudo lsof -i :22

# Instantly kill process on port 22
lsof -ti:22 | xargs kill -9

Windows (PowerShell & CMD)

# Find PID listening on port 22
netstat -ano | findstr :22

# Force kill by PID
taskkill /PID <PID_NUMBER> /F

Cross-Platform Node.js One-Liner

# Kill port 22 via npx
npx kill-port 22

# Or diagnose via Castov CLI
npx castov fix "EADDRINUSE :::22"

Linux Firewall (UFW) & Connectivity Test

# Test if port 22 is reachable
nc -zv localhost 22

# Allow or deny port 22 in UFW
sudo ufw allow 22/tcp

Frequently Asked Questions about Port 22

What is Port 22 used for?

Port 22 is the standard network port for SSH / SFTP (Secure Shell, SCP, SFTP, and Port Forwarding) operating over TCP. The typical system daemon or process is sshd.

How do I kill a process running on Port 22 (EADDRINUSE)?

On macOS and Linux, run: lsof -ti:22 | xargs kill -9 (or npx kill-port 22). On Windows PowerShell/CMD, run: netstat -ano | findstr :22 and then taskkill /PID <PID> /F.

Is it safe to expose Port 22 to the internet?

Port 22 has a Medium security risk profile. Standard port for encrypted remote administration, Git over SSH, and SFTP file transfers. Harden with key-based authentication and fail2ban.