IP subnet calculator for IPv4 and IPng

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The part IPv6 calculator is a beta version. please help me to correct it. Discussions under the user PEPJ [plugin ipsubnet] in http://www.cactiusers.net or http://forums.cacti.net/. I am unsure for the subnet theorie in IPv6 because the RFCs give very few information) 

IPv6 Address:
bits   3     13    32   16   64
      FP     TLA   NLA  SLA  Interface identifier
