TFTP server, short for Trivial File Transfer Protocol server, is a network protocol used to transfer files between devices on a network. TFTP is a simple protocol that is often used for tasks such as firmware updates or transferring configuration files.
There are a few different ways to check if a TFTP server is running on a network. One way is to use the `tftp` command to attempt to transfer a file from the server. If the transfer is successful, then the server is running. Another way to check is to use a network sniffer to look for TFTP traffic on the network. If TFTP traffic is detected, then the server is running.