Internet-Security.com UDP port 69 details

UDP port 69 is used by the Trivial File Transfer Protocol (TFTP).
PXE network boot relies on TFTP for boot files in systems like Microsoft Windows Deployment Services (WDS), iPXE/PXELINUX (Syslinux), the FOG Project, and OpenStack Ironic (often via dnsmasq).
Network gear uses TFTP to move firmware/configs, including Cisco IOS/IOS-XE/ASA, Juniper Junos, MikroTik (Netinstall/RouterBOOT), and Ubiquiti devices (e.g., TFTP recovery for UniFi/EdgeOS).
Many IP phones fetch configurations/firmware via TFTP, such as Cisco Unified IP Phones, Avaya, and Poly/Polycom models.
Common TFTP servers include tftpd-hpa and atftpd (Linux), dnsmasq’s built-in TFTP, SolarWinds TFTP Server, and Tftpd64/Tftpd32 and OpenTFTPServer (Windows).
Printers and embedded devices often use TFTP for firmware recovery, e.g., HP JetDirect printers and cameras from Hikvision and Dahua.
Security: TFTP lacks authentication and is frequently abused for unauthorized file transfer; for example, the Blaster worm used TFTP to pull its payload, and misconfigured TFTP servers have exposed device configs.

UDP 69