GNU/Linux - How to install and configure a TFTP server

Last updated: Feb 26, 2025

TFTP (Trivial File Transfer Protocol) is a simple File Transfer Protocol that allows a client to get or put a file to a remote host.

It is an old protocol, but it is still used in many network applications.

Personally, I use it to update the firmware of my network equipment. (e.g. Cisco switches).

Here's how to set up a TFTP server on Debian.

Network Diagram

OS: Debian 12 (bookworm)
Tftp server: atftpd
Network Protocol: UDP 69
Tftp directory: /srv/tftp

Diagram illustrating the setup of a TFTP server on Debian, showing a laptop connected to a local area network (LAN) with IP addresses and a TFTP folder containing necessary files. — Debian tftp server architecture

Installation

Update package sources list:

root@server:~# apt update

Install the atftpd package:

root@server:~# apt install atftpd

Create a /srv/tftp folder. We will use this as the root tftp share:

root@server:~# ls /srv/tftp || mkdir -p /srv/tftp

Configuration

Network Configuration

Edit the file /etc/network/interfaces (replace ens224 by your own network interface):

allow-hotplug ens224
iface ens224 inet static
        address 192.168.1.10
        netmask 255.255.255.0
        gateway 192.168.1.254
	dns-nameservers 192.168.1.254

Restart the system or network service so that changes are taken into account:

root@host:~# systemctl restart networking

TFTP service configuration

Edit /etc/default/atftpd and check that you have the same settings:

USE_INETD=true
# OPTIONS below are used only with init script
OPTIONS="--tftpd-timeout 300 --retry-timeout 5 --mcast-port 1758 --mcast-addr 239.239.239.0-255 --mcast-ttl 1 --maxthread 100 --verbose=5 /srv/tftp"

Restart the atftpd service:

root@server:~# systemctl restart atftpd.service

Set read and write permissions so that the files in /srv/tftp are readable and writable:

root@server:~# chmod -R ugo+rw /srv/tftp/

Checking from a client

To check that our server is working properly, we can use a TFTP client.

If you are using a Debian machine (which is a good choice!), install the TFTP client:

root@client:~# apt update && apt install tftp

Connect to the TFTP server:

user@client:~$ tftp 192.168.1.10

Show status:

tftp> status
Connected to 192.168.1.10.
ode: netascii Verbose: off Tracing: off
Rexmt-interval: 5 seconds, Max-timeout: 25 seconds

Download a file:

tftp> get c1000-universalk9-mz.152-7.E4.bin

Send a file:

tftp> put c1000-universalk9-mz.152-7.E4.bin

Exit session:

tftp> quit

DHCP server

In some situations, setting up a DHCP server may be necessary. Here is how to do it.

Install the dhcpd service:

root@client:~# apt update && apt install isc-dhcp-server

Edit the /etc/dhcp/dhcpd.conf file, here with an address pool from 192.168.10.10 to 192.168.10.20:

option domain-name "example.org";
default-lease-time 600;
max-lease-time 7200;
ddns-update-style none;

subnet 192.168.10.0 netmask 255.255.255.0 {
  range 192.168.10.10 192.168.10.20;
}

Edit the /etc/default/isc-dhcp-server file and specify the network interface on which the dhcp service will run:

INTERFACESv4="ens224"
#INTERFACESv6=""

Restart the dhcpd service:

root@client:~# systemctl restart isc-dhcp-server.service

Show the dhcpd leases:

root@client:~# grep dhcpd /var/log/syslog