Advanced network config:
One advanced network option has to do with reseeding - you should never need to reseed your router as long as you can find at least one other peer on the network. However, when you do need to reseed, a link will show up on the left hand side which will fetch all of the routerInfo-* files from http://dev.i2p.net/i2pdb/. That URL is just an apache folder pointing at the netDb/ directory of a router - anyone can run one, and you can configure your router to seed off an alternate URL by adding the java environmental property "i2p.reseedURL=someURL" (e.g. java -Di2p.reseedURL=http://dev.i2p.net/i2pdb/ ...). You can also do it manually by getting routerInfo-*.dat files from someone (a friend, someone on IRC, whatever) and saving them to your netDb/ directory.