Lee Seidman wrote: > I can't say much for proxy ports, but for my > environment (urban public high school), I did a brief > search on CNET.com and ZDNET.com and through Windows > 2000 policies prohibited those particular P2P programs > from being executed. There were really only about 10 > or 12; the most popular are Morpheus, Gnutella, KaZaa, > and BearShare that I have encountered. > > Against more sophistocated users, this may not work so > well; but thus far it has been pretty prohibitive.
If you have a closed network with a proxy as the only way out to the Internet, and your proxy supports ACLs against a User-Agent header, you could blacklist all User-Agents, except the ones you want to allow, eg: ".*Mozilla.*" and ".*IE.*" etc etc.. You could block out all the P2P and any other unknown clients, without constantly keeping updated port/program lists. Of course it's not perfect, someone could hex edit the banner, or write a proxy which rewrites the banner to something thats allowed.. But it's an idea, anyway. Squid is a proxy which can ACL on many (all?) HTTP headers. Regards, Chris.
