I guess I won't be forgetting about hosts.allow next time. This is one case where ping will work but TFTP will fail, even with no firewall running.

The routers that were one hop away used that allowed network to get back to the TFTP server (via static routes on the cable router), but the one router directly connected was on a network not listed in hosts.allow (and I have ALL:ALL in ny). In my case, I found that my hosts.allow file on the TFTP server box was only configured to allow the network with the cable router and no other networks. One of my routers was directly connected to the network with the raspberry pi and it was NOT connecting! It could ping the IP address just fine, but no TFTP. Two of my routers were each one hop away from the TFTP server (a raspberry pi). I had to enter static routes on the dlink to get packets back to the cisco routers. TFTP has been used for this application because it is simple to implement.

One of its primary uses is in the early stages of nodes in a network booting from a server. I have them all connected to my cable internet router (dlink dgl-4500). Tftp Linux Credit: Trivial File Transfer Protocol (TFTP) is a simple, lockstep FTP that allows a client to get a file from or put a file onto a remote host. I have 3 routers (two 1841's and one 2801) and 3 switches (all 2950's) for my CCNA lab at home.

Tftp server linux