Port 69 (TFTP)

Trivial File Transfer Protocol, used for network boot (PXE) and device configuration files.

Transport
UDP
Internet exposure
Never expose

Should not be reachable from the internet.

Security notes

  • No authentication at all: anyone who can reach it can read, and sometimes write, files.
  • Exposed TFTP servers have leaked router and VoIP phone configurations including credentials.

When it shows up in your logs

TFTP across network boundaries is unusual and worth checking.