Is there a way to block by IP address? and why are my ftp logs not being saved?

I have my sharespace sitting out on the internet so that I can share through ftp with several friends and neighbors.  I’ve noticed the logs have been showing a lot of attempts to access it by IP addresses that are not my friends or neighbors.  one of them is actually on the same ISP cable modem network as me and has been trying to get in through CIFS.  I’m not very 'nix savy but isnt there a file I can add IPs to and block these unwelcome trespassers?

Also, I upped my log size significantly when I noticed the hits from a chinese IP address and then I cleared the logs so I could keep an eye on any new activity easily.  since then my ftp log only shows the last 3 entries and nothing else… any idea how I can fix that?

and also… is the ssh password really limited to 8 characters?  any way to up that?  

how eaxctly do you want to block the ip? Do you mean showing up as anonymous give a example