What TFTP function is used in network device maintenance?

TFTP (Trivial File Transfer Protocol) is commonly used in network device maintenance for transferring IOS images from a server to a router or switch. It's a simple, connectionless protocol that doesn't require authentication, making it suitable for quick, local transfers within a trusted network segment, especially during firmware upgrades. While TFTP can transfer configuration files, it lacks security features like username/password authentication, which is typically handled by more secure protocols like SCP or SFTP. TFTP is not ideal for congested links due to its lack of flow control and error recovery mechanisms. Transferring files between file systems on a router is typically done via internal commands or a more robust file transfer protocol if an external server is involved.