TFTPD

TFTPD is a software implementation of the Trivial File Transfer Protocol (TFTP) server. TFTP is a simple network protocol used for transferring files between a client and a server. It is often used in network booting scenarios, firmware updates for network devices, and for simple file transfers where the overhead of full FTP is undesirable. TFTPD, as a server, listens for incoming TFTP requests from clients.

The protocol operates over UDP (User Datagram Protocol), making it connectionless and generally faster than TCP-based protocols for simple transfers but also less reliable. TFTPD handles requests to read files from the server (RRQ) and write files to the server (WRQ). It implements the necessary mechanisms for packet acknowledgment, error handling, and retransmission if packets are lost, although its error handling is more basic than that of FTP.

Various implementations of TFTPD exist across different operating systems and for different purposes. Some are standalone daemons, while others might be integrated into larger network management tools. Common use cases include network booting of diskless workstations, where a TFTP server provides the initial operating system image. It is also frequently used by network administrators to upload or download configuration files to and from routers, switches, and other network hardware. Due to its simplicity and lack of authentication, TFTPD is typically deployed in controlled network environments. Security considerations are important, as TFTP does not provide any authentication or encryption, making it vulnerable in unsecured networks.