###Synopsis

This module provide a method to tackle with network attacks.
eg , you could set the LIMIT number of connections a client/ip could hold
when it reaches to this limit , just close the socket...

###Usage

After you create a tcp/http server :

  var MAX_CONN_PER_IP = 10;
  var doFilter = require('./server_filter').fn;
  doFilter(server, MAX_CONN_PER_IP);