TFTP (Trivial File Transfer Protocol) primarily uses port 69.
However, a more complete answer involves understanding how TFTP uses ports for data transfer. Here's a breakdown:
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Default Port: The TFTP server listens on UDP port 69 for client requests. This is the well-known port for TFTP. The reference states: "Port 69 is the default port for TFTP..."
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Data Transfer: After the initial connection on port 69, the server and client negotiate a new, randomly assigned UDP port for the actual data transfer. This means that while port 69 initiates the transfer, the file data isn't sent over port 69. It is sent over a dynamic port chosen for that specific session.
TFTP Port Usage Summary
| Protocol | Port | Purpose |
|---|---|---|
| UDP | 69 | Initial connection and request negotiation |
| UDP | Dynamic | Data transfer (negotiated after connection) |
It's important to note that while port 69 is the default, it can be changed on the server. The reference mentions: "...you can modify the settings on your TFTP server so it runs on a different port." However, this is not typical.
