Port 69
Trivial File Transfer Protocol (TFTP)
Trivial File Transfer Protocol (TFTP) is a simple, lightweight file transfer protocol used primarily within local networks for transmitting files without the complexities of authentication or directory visibility. It's typically used for bootstrapping devices, transferring firmware, or configuration files in a controlled environment..
Technical Details
Overview:
TFTP, standardized under RFC 1350, is a simple lock-step protocol that allows a client to get or put a file onto a remote host. It utilizes UDP for communication, favoring speed and simplicity over guaranteed delivery. The protocol is especially effective in closed, reliable environments such as provisioning embedded devices.
Protocol Details:
Operating over UDP port 69, TFTP uses simple request and response messages—specifically read request (RRQ), write request (WRQ), data (DATA), acknowledgment (ACK), and error (ERROR) packets. The file transfer is split into fixed-size blocks (default 512 bytes), which must each be acknowledged by the receiver, ensuring some measure of flow control despite the unreliable nature of UDP.
Typical Applications:
TFTP is predominantly found in scenarios where minimal configuration and ease of implementation are required, such as:
- Booting diskless workstations and network devices (via PXE)
- Transferring firmware updates
- Backing up network device configurations
- Embedded system deployments Its simplicity allows for small code footprint implementations suitable for embedded environments.