Port 69 / UDP
TFTP
Port 69 – TFTP Protocol Specification
Technical analysis, security advisories, vulnerability mitigation, and firewall syntax for TCP/UDP port 69 (TFTP).
Port Number
69
Transport Protocol
UDP
Port Range Type
Well-Known (0-1023)
Default Status
Restricted / LAN
Service Description & Architectural Context
Trivial File Transfer Protocol used for PXE network booting.
IANA / RFC Designation:
Port 69 is assigned to TFTP under the Internet Assigned Numbers Authority (IANA) service name registry. In enterprise infrastructure and homelab setups, services listening on this port must follow the principle of least privilege.
Security Analysis & Attack Surface Assessment
Zero authentication or encryption. Restrict to isolated provisioning VLAN.
Hardening Recommendations:
- Do not expose port 69 to public WAN interfaces unless authenticated TLS or VPN wrapping is strictly enforced.
- Enforce rate-limiting using Fail2ban, CrowdSec, or cloud edge DDoS protection.
- Audit active listening sockets locally:
ss -tulpn | grep :69ornetstat -ano | findstr :69.
Firewall Rule Snippets for Port 69
UFW (Ubuntu / Debian Linux)
sudo ufw allow 69/udp
iptables (Standard Linux Kernel)
sudo iptables -A INPUT -p udp --dport 69 -j ACCEPT
Windows PowerShell (Defender Advanced Firewall)
New-NetFirewallRule -DisplayName "Allow Port 69" -Direction Inbound -LocalPort 69 -Protocol UDP -Action Allow