Port 22 (TCP) — SSH / SFTP / SCP
Secure Shell (SSH) provides encrypted remote terminal administration, SFTP file transfers, and port-forwarded tunnels across Linux, BSD, router, and cloud instances.
| Port Number | 22 |
|---|---|
| Transport Protocol | TCP |
| Primary Service | SSH / SFTP / SCP |
| Standard / Specification | RFC 4251 / RFC 4253 |
| IANA Port Range | Well-Known System Port (0–1023) |
| Internet Exposure Risk | High if password auth is exposed publicly; restrict to bastion CIDRs or VPN. |
Firewall Architecture & Hardening Best Practices
Disable root password login (PasswordAuthentication no), enforce Ed25519 public-key authentication, and restrict inbound TCP/22 in cloud Security Groups to corporate egress IPs or a WireGuard management subnet.
Operational Troubleshooting Note
If SSH connects but freezes during large directory listings (ls -la) or Git pushes over VPN, suspect a Path MTU black hole and lower tunnel TCP MSS.
Quick CLI Connectivity & Firewall Reference
# Test TCP/22 reachability (Linux / macOS / PowerShell) nc -zv target.example.com 22 Test-NetConnection -ComputerName target.example.com -Port 22 # Allow restricted CIDR on Linux UFW firewall ufw allow from 10.0.0.0/8 to any port 22 proto tcp
Planning firewall allowlists or VPN overlays? Use our IPv4 CIDR Calculator, MTU & TCP MSS Calculator, or WireGuard AllowedIPs Generator.
Browse Common Network & Cloud Ports
Port 22 (SSH) Port 25 (SMTP Mail Relay) Port 53 (Domain Name System) Port 67 (DHCPv4 Server) Port 80 (HTTP Web Traffic) Port 123 (Network Time Protocol) Port 161 (SNMP Polling) Port 179 (Border Gateway Protocol) Port 389 (LDAP Directory) Port 443 (HTTPS & HTTP) Port 445 (SMB Direct File Sharing) Port 465 (SMTPS Implicit TLS Submission) Port 500 (IPsec IKEv2 Key Exchange) Port 514 (Syslog Telemetry) Port 587 (SMTP Mail Submission) Port 636 (LDAPS) Port 853 (DNS over TLS) Port 993 (IMAPS Encrypted Mailbox) Port 1194 (OpenVPN Tunnel) Port 1433 (Microsoft SQL Server) Port 1812 (RADIUS Authentication) Port 2049 (Network File System) Port 2379 (etcd Client API) Port 3306 (MySQL & MariaDB) Port 3389 (Remote Desktop Protocol) Port 4500 (IPsec NAT Traversal) Port 5432 (PostgreSQL Database) Port 6379 (Redis) Port 6443 (Kubernetes API Server) Port 51820 (WireGuard VPN)