code: public boolean isPrivate() {
  		// refer to RFC 1918
          // 10/8 prefix
          // 172.16/12 prefix (172.16.0.0 – 172.31.255.255)
          // 192.168/16 prefix
  		IPv4AddressSegment seg0 = getSegment(0);
  		IPv4AddressSegment seg1 = getSegment(1);
  		return seg0.matches(10)
  			|| seg0.matches(172) && seg1.matchesWithPrefixMask(16, 4)
  			|| seg0.matches(192) && seg1.matches(168);
  	}
docs: Unicast addresses allocated for private use
  
  @see java.net.InetAddress#isSiteLocalAddress()