TFTP looks like a bad file protocol — no login, no encryption, no folders. Inside switches, routers and boot firmware it is exactly the right tool. Here is what it is genuinely for, what it must never be used for, and how it honestly compares with FTP and SFTP.
Every protocol survives because it fits one job perfectly. TFTP's job is moving a small file to or from a device that has almost no software on it — a switch booting up, a router recovering, a PC starting over the network. It was designed in 1981 to fit inside tiny boot code, and that is still why your switch offers copy running-config tftp: and not an SFTP menu. Understanding that one fact tells you both where TFTP shines and where using it would be a mistake.
This is the classic TFTP job, and the one in the video series. A switch or router holds its whole personality in one configuration file, and its copy commands speak TFTP natively. Thirty seconds of work gives you a text file you can restore after a failed change or a dead device. No other protocol is offered by as many devices, which is the entire reason TFTP is still alive.
Many switches, routers, wireless controllers and IP phones load their firmware image from a TFTP server. The device's bootloader contains just enough code to ask the network for one file — TFTP is small enough to be that code. The file sizes are modest, the network is local, and the transfer either completes with a correct checksum or the device refuses the image.
When a PC boots from the network, DHCP tells it which server holds the boot file, and the file itself is fetched by TFTP. That is how imaging systems start hundreds of machines. Notice the pattern: in PXE, as in firmware, TFTP is used at the one moment when the machine has no operating system yet — there is nothing on it that could run a bigger protocol.
The honesty list is short and absolute:
TFTP — no authentication, no encryption, UDP port 69, almost no features. Exists because boot firmware can implement it in a few kilobytes.
FTP — has usernames and passwords, but plain FTP sends them unencrypted, along with the data. It survives in legacy equipment. If a device offers FTP and TFTP only, FTP is not automatically "more secure" — on a hostile network both are open; on a trusted LAN both are workable, and TFTP is simpler.
SFTP — a completely different protocol riding inside SSH: real login, full encryption, integrity checks, TCP port 22. This is the correct default for file transfer between computers, and the only one of the three that should ever cross a network you do not control. Its limitation is the mirror image of TFTP's strength: a switch bootloader cannot contain an SSH stack, which is why devices still speak TFTP.
If the device itself is asking for the file — firmware, config, boot image — and everything stays on one trusted LAN, TFTP is the right and normal tool. If a person is moving files, or anything leaves that LAN, use SFTP. Choosing between them is not about old versus new; it is about which side of that line your job sits on.
The full TFTP server setup — installation, root folder, firewall and a live transfer — is shown step by step in the video.
▶️ Watch Full VideoBecause of size. A switch or router must be able to fetch firmware and configurations from its smallest boot code, before its full operating system loads. TFTP is tiny enough to live in that boot code and simple enough to be reliable there. An SSH/SFTP stack is far too large for that layer, so TFTP remains the device-level standard.
Only slightly, and not in the way most people assume. Plain FTP does ask for a login, but it sends the password and the data unencrypted, so anyone watching the network can read both. On a trusted LAN either protocol is acceptable for device work; on an untrusted network neither is — use SFTP.
For normal device firmware, yes. The protocol acknowledges every block, and modern implementations negotiate larger block sizes to speed things up. A failed or corrupted transfer is detected because the block sequence breaks. For very large files between computers, though, TFTP is simply the wrong tool — SFTP is faster and resumable.