TFTP time out in Ubuntu?

Question

I've got a 2620xm plugged into my ubuntu laptop. There's a TFTP server running on the laptop. Both devices are plugged into each other with a cross over cable.

I couldn't copy my IOS from the 2620xm to the laptop, so I tested the tftp on the laptop by having it connect to itself:

tftp 192.168.3.4
put test.txt
Transfer timed out.

my tftp config is:
{
protocol = udp
port = 69
socket_type = dgram
wait = yes
user = root
server = /usr/sbin/in.ftpd
server_args = -u root -c -s -r blksize /tftpboot
disable = no
flags = IPv4
}

my /etc/hosts.allow has:
in.tftpd : 192.168.3.3
in.tftpd : 192.168.3.4

I've restarted xinetd a number of times...

user "nobody" owns the /tftpboot directory and its been chmod 777.
user "nobody" also owns test.txt and its been chmod 777.

I read somewhere about tftp having some weird authentication hole:
"Note that tftp has NO built-in authentication. Therefore, in order to avoid a huge security hole, they made the hole a bit smaller by refusing to work if the data directory is writeable."

http://ubuntuforums.org/showthread.php?t=1615780

I also turned off the firewall:

sudo ufw disable

And nothing!

It's amazing how hard this is to get working... I'm a certified linux tech and I'm totally stumped.

Any ideas?

Answer 1

Timeouts are almost always from firewall or connection issues. You should try:

1.) Pinging the LAN IP from both machines to make sure the IP can be reached.

2.) Make sure iptables isn't getting in the way (run iptables-save, probably in /sbin/)

3.) Make sure there are no problematic entries in /etc/hosts.deny



If those are fine, try:

1.) Make sure tftp is actually listening on UDP port 69: netstat -aunp | grep ":69 "

2.) Use nc (netcat) with UDP to ensure that you can connect remotely on UDP port 69.

Answer 2

Tftp Transfer Timed Out

Answer 3

I believe the problem is that you are using a crossover cable. Try hooking up to the router with a regular Ethernet cable and see if you still have the same issue