I am in the process of replacing our TFTP servers. They run Linux (Fedora) and tftp-hpa. We have a bunch of Toshiba cable modems on our network (PCX1100U) and these modems can't download the config files on the new severs. All other modems can.
I have tried other tftp servers such as atftp and tftpserver. No matter what I do the Toshiba's won't download their config files. Through logging this appears to be a timeout issue. I've tried adjusting the timeout value but it doesn't make a difference.
Has anyone run into the problem before? Replacing these modems is not an option.
To answer my own question in case someone has this problem:
This server has two network interfaces. The first is used for administration and is the default gateway. The second is connected to the cable modem network. The cable modems are on a separate subnet. To fix the problem I just needed to add a persistent route to the cable modem network.
I'm not sure why all the other cable modems were able to download the config file.