In the olden days, inetd ruled the roost and was responsible for letting many local services out onto the network so that they could communicate with other users and machines.
#Linux tftp server how to
Let’s look at how to get a TFTP server up and running. Listing 1: The type of transaction that you may see when backing up a network device’s config via TFTP.Īs you can see in this listing, the exclamation marks provide a progress bar of sorts and each one acts as an indicator that a successful transfer of ten packets. On a network device, for example, you might encounter a transaction similar to that seen in Listing 1: Router# copy running-config tftp: Address or name of remote host ? 10.10.10.10 Destination filename ? router_config_backup_v1 !!!! 3151 bytes copied in 1.21 secs (2,604 bytes/sec) Router#
Many of the major vendors still prefer this method, possibly because there’s a feeling of comfort (in relation to security) when moving files around inside a LAN relative to doing so across the Internet. If you’ve ever maintained switches or routers, then you’ve likely used TFTP either to back up or restore config files or possibly to perform a firmware upgrade. This functional simplicity is definitely a bonus. It tends to work or it doesn’t there’s little middle ground. Also the number of parameters required to retrieve a file (and therefore the number of things that can go wrong) is very limited. Why choose TFTP over FTP or even HTTP, you may ask? Simply because even if you don’t have a TFTP server already up and running, it’s relatively easy to quickly get started. You may also want to use TFTP - as several vendors do - for firmware updates.
#Linux tftp server software
It might also be used during boot time to pull the latest version of a file from a local server so that all clients are guaranteed to be up-to-date with a certain software package.
If you’re creating new machines from images, then TFTP is perfect for bootstrapping a new server with predefined config and a sprinkling of packages. Now that you’re firmly sold on using this somewhat-deprecated protocol, let’s have a think about what it might be used for. Admittedly, there may have been improvements since its original design but the RFC also states that, in essence, the only errors it can pick up are noticing if the wrong user is specified, if a file that’s requested doesn’t exist, and other access violations. Other somewhat surprising limitations, relative to its cousin FTP, include a lack of authentication and the ability to delete or rename files. If you want to use TFTP, you need to be aware of the filenames, which are sometimes complex and lengthy to provide a small dose of security through obscurity, before connecting to a server.
Unlike the well-known FTP service, which is commonly used for moving files back and forth across the Internet (and which includes successors with encryption, such as sFTP and FTPS, among its family members), TFTP doesn’t even allow the listing of directories, so you can see which files are available. The feature set included with TFTP is admittedly quite limited but, make no mistake, it can still be very useful on a local area network (LAN). TCP offers resilience through error recovery but instead TFTP uses the User Data Protocol (UDP) presumably because of the “trivial” nature of its file transfers. In an unusual twist, TFTP doesn’t use the now almost mandatory Transmission Control Protocol (TCP) for moving its data around. That may not be the 1970s but FTP and TFTP can certainly be considered founding protocols. The other day, I was using Trivial File Transfer Protocol (TFTP) and looked up its Request For Comments (RFC) only to discover that it’s been around a while longer than I suspected: since June 1981 to be exact. Sometimes we find ourselves using technologies that - although we may not realize it - stem from way back in the history of the Internet.