# TFTP Protocol Agent

The Trivial File Transfer Protocol (TFTP) Protocol Agent performs data transfer from a server to a client using dynamically selected ports.

There are no specific limits to the port range in the TFTP protocol (RFC 1350). Apart from Access rules, the TFTP Protocol Agent is also useful in NAT operations on Firewalls.

A TFTP Agent is attached to a UDP connection established between the client and the server. The client opens the control connection from a dynamically selected source port to the fixed destination port 69/UDP on the server. A separate UDP data connection is established between the client and the server after the client has sent a read or write command to the server. The server opens a connection from a dynamic source port to the client’s destination port. The destination port is the same as the source port in the control connection.

On Firewalls, this agent has parameters you can set in the Service properties. On IPS engines and Layer 2 Firewalls, there are no configurable parameters for this Protocol Agent.