sudo apt-get update
sudo apt-get install tftp-hpa
sudo /etc/init.d/networking stop
sudo ifconfig eth0 192.168.11.2
sudo ifconfig eth0 netmask 255.255.255.0
sudo arp -s 192.168.11.1 02:AA:BB:CC:DD:20
#change to the folder where you put the firmware image, if it's on desktop then it's
#"/home/ubuntu/Desktop".
cd /home/ubuntu/Desktop
tftp 192.168.11.1
*from this point, you're under tftp command prompt, the "tftp>" is the prompt tftp gives you, you just need to type the command AFTER that.
tftp> verbose
tftp> binary
tftp> trace
tftp> rexmt 1
tftp> timeout 60
tftp> put wzrg300nh-firmware.tftp
Now the important things that I found out.....I had to use a swit**ub with my dektop plugged into it and the bricked Buffalo into another port. I think from what i read this is because you don't want the network card to intialize when you power up the Buffalo. Secondly you have to use the MAC address i noted above (i found this address in another post here)
This post also seems to indicate that the wait period is 2 secs so it's a timing thing. But it worked for me in resolving a bricked unit (Solid DIAG light )