| Metric | Value | | :--- | :--- | | | Very low (≈1.2 MB/s on LAN due to ACK delay). | | Optimized (blksize 1456 bytes) | Up to ~10 MB/s on gigabit LAN. | | Windowed mode | Not in standard TFTP; requires proprietary extensions (e.g., tftp-multicast). | | Latency dependence | Highly sensitive to RTT; unusable over high-latency satellite links without blksize tuning. |
sudo launchctl load -F /System/Library/LaunchDaemons/tftp.plist TFTP Server
It sends data in fixed 512-byte blocks.
Client Server | | | ---- Read Request (RRQ) [Port 69] -----> | | | (Server chooses random TID port) | <--- Data Block 1 [TID Port] ----------- | | ---- Acknowledgment 1 -----------------> | | <--- Data Block 2 ---------------------- | | ---- Acknowledgment 2 -----------------> | | | | Metric | Value | | :--- | :--- | | | Very low (≈1
Because TFTP uses UDP, it cannot rely on the connection to ensure data arrives intact. Instead, it uses a "lockstep" mechanism: | | Latency dependence | Highly sensitive to
To put TFTP into perspective, it helps to see how it stacks up against other file transfer methods:
| Feature | TFTP | FTP | SFTP (SSH) | | :--- | :--- | :--- | :--- | | Transport | UDP | TCP (21, 20) | SSH (TCP 22) | | Authentication | None | Plaintext | Strong (pubkey/password) | | Encryption | None | None (except FTPS) | Full | | Directory listing | No | Yes | Yes | | Data integrity | Basic checksum (optional extension) | TCP checksum | SHA-256 hashing | | Complexity | Very low | Medium | High | | Typical use | PXE boot, firmware | User file transfer | Secure file transfer |