The Internet Protocol Address Calculator is an open-source java-based tool. This calculator will assist network administrators to perform calculations over both IPv4 and IPv6 address space. A handy whois search client is also integrated into this tool.
Dynamically update your network's external IP address to a host name service such as DHS International (dhs.org) or DynDNS.org (dyndns.org) so that you can access your network using a host name. Even works behind routers such as Linksys and Netgear.