We based our router on the Python starter code that was provided. We built functionality in the order of data, dump, and update for the first milestone, using the functions provided as scaffolding.
The first obstacle we encountered was understanding how Unix Domain sockets worked. Once we wrapped our head around that, the majority of the first milestone went well. The largest headache we had was determining which IPs to use as the source and destination fields when sending update information. Once we figured this out however, the milestone was achieved.
We used the configuration files and the sim to test the robustness of our router at this point, and used error catching blocks to handle issues that could occur.