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.