How can I make my tftp server visible/available on my local network?

networking server iptables tftp

9,417

Since you have only INPUT rules, which means you only accept incoming traffic from port 69 but you have traffic going out aswell, that means you need to ACCEPT outgoing traffic aswell.

sudo iptables -A OUTPUT -p tcp --dport 69 -j ACCEPT
sudo iptables -A OUTPUT -p udp --dport 69 -j ACCEPT

9,417

Alex Meuer

Updated on September 18, 2022

Comments

Alex Meuer over 1 year
I have looked at the following questions without success:
I've tried using tftp-hpa, atftpd and tftp. I've returned to tftp as using the others made no difference.

So far I have:

Installed tftp
```
sudo apt-get install xinetd tftpd tftp
```
Set up /etc/xinetd.d/tftp
```
service tftp
{
protocol        = udp
port            = 69
socket_type     = dgram
wait            = yes
user            = nobody
server          = /usr/sbin/in.tftpd
server_args     = /tftpboot
disable         = no
}
```
Created the /tftpboot folder and ran the following for it:
```
sudo chmod -R 777 /tftpboot
sudo chown -R nobody /tftpboot
```
I have allowed port 69 through iptables:
```
sudo iptables -A INPUT -p tcp --dport 69 -j ACCEPT
sudo iptables -A INPUT -p udp --dport 69 -j ACCEPT
sudo iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:tftp
ACCEPT     udp  --  anywhere             anywhere             udp dpt:tftp
```
and restarted the service:
```
sudo /etc/init.d/xinetd restart
```
I can connect fine using localhost (same result if I explicitly use 127.0.0.1):
```
tftp localhost
tftp> status
Connected to localhost.
Mode: netascii Verbose: off Tracing: off
Rexmt-interval: 5 seconds, Max-timeout: 25 seconds
tftp> get test
Received 21 bytes in 0.0 seconds
tftp> quit
```
However, none of my colleagues can access it from their machines (same network, same subnet mask) and, most importantly, I can't access it from the embedded board that I need it for (ethernet cables plugged into same switch). I've been googling for hours and haven't found a fix yet.

The fact that it works locally would suggest its a firewall/port problem but port 69 is allowed on iptables and I'm not sure what else I an do.
- Gen almost 8 years
  
  Can you try telnet from your colleague for port 69 to your machine? If it does/doesn't work, let me know.
- Alex Meuer almost 8 years
  
  I'm using tftp 10.42.143.17 from another pc, and load -b tftp://10.42.243.17/zbimage-linux-xload from the embedded system. According to other questions and tutorials udp port 69 is the default for tftp.
- Alex Meuer almost 8 years
  
  @Gen Telnet on port 69 fails.
- Gen almost 8 years
  
  @AlexMeuer this means problem is at firewall inside your server or router. To be sure make same iptables rules for output, just change INPUT to OUTPUT and let me know if problem still exist.
- Alex Meuer almost 8 years
  
  @Gen Adding the OUTPUT rules fixed my problem. Thank you so much!
- SPRBRN almost 8 years
  
  With problems like these, disable the firewall, then test again.