My internet provider has provided me a Fritz!Box Fon 3970, which is a neat all-in-one modem / router / voip and DECT connectivity box. Although this box is running Linux and pretty extendible with Freetz, in some area's it is a pretty closed black (erm.. red) box and sometimes it is hard to debug problems.
Today, while debugging issues with my DHCP server, I found out that the standard Fritz!Box firmware includes a handy network tracer. To trace network traffic (all or just on a specific interface), go to http://fritz.box/capture.lua and specify which interface to start the trace on.
The output will be provided through a download that starts immediately. The resulting file can be opened using Wireshark for analysis.
I didn't solve my DHCP problem yet (the DHCP server is still only giving WLAN clients and IP address and not to wired clients), but that's something I will tackle over the weekend now that I can obtain a decent network trace from the box.
While migrating my linux-based server to Mac OS X Lion Server, I noticed it did not have a TFTP server enabled by default. A little googling pointed me to a blog post of The Weezey Geek, who outlined that everything is there, it's just disabled.
Which makes the change permanent and starts the TFTP daemon.
To allow TFTP uploads, make sure that the directory to be uploaded to (be wise and make this a subdirectory of your TFTP root directory) is writable to all users.