🔌 Well-Known Ports Reference
TCP and UDP port numbers for common services. Search by port number, service name, or use case. Includes diagnostic commands.
Diagnostic Commands
Check who's listening on a port
ss -tlnp sport = :PORT lsof -i :PORT netstat -tlnp | grep PORT
Check if port is open on remote host
nc -zv host PORT telnet host PORT curl -v telnet://host:PORT
Scan for open ports (nmap)
nmap -p 1-1024 host nmap -sU -p 53,67,123 host # UDP nmap -p- host # All 65535 ports
Show all listening sockets
ss -tlnp # TCP listening ss -ulnp # UDP listening ss -tlnp6 # IPv6 only
| Port ▼ | Proto | Service | Description | Category |
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