Port 69 — TFTP

UDP well-known

What runs on port 69

Trivial FTP, used for network boot and switch firmware.

Security considerations

No authentication at all by design. Confine it to an isolated provisioning network.

Checking whether something is listening

# Linux / macOS — what is bound to the port
sudo lsof -i :69
sudo ss -lntp | grep :69

# Windows
netstat -ano | findstr :69
Get-NetTCPConnection -LocalPort 69

# is it reachable from outside?
nc -zv example.com 69
curl -v telnet://example.com:69

Freeing the port

# find the process, then stop it
sudo lsof -ti :69 | xargs kill        # Linux / macOS
netstat -ano | findstr :69            # note the PID, then:
taskkill /PID <pid> /F                    # Windows

Other common ports

• Port 20 — FTP data
• Port 21 — FTP control
• Port 22 — SSH / SFTP
• Port 23 — Telnet
• Port 25 — SMTP
• Port 53 — DNS
• Port 67 — DHCP server
• Port 68 — DHCP client
• Port 80 — HTTP
• Port 110 — POP3
• Port 123 — NTP
• Port 143 — IMAP
• Port 161 — SNMP
• Port 389 — LDAP
• Port 443 — HTTPS
• Port 445 — SMB
• Port 465 — SMTPS
• Port 514 — Syslog

All port numbers