NAME
    Tie::NetAddr::IP - Implements a Hash where the key is a subnet

SYNOPSIS
      use Tie::NetAddr::IP;

      my %WhereIs;
  
      tie %WhereIs, Tie::NetAddr::IP;

      $WhereIs{"10.0.10.0/24"} = "Lab, First Floor";
      $WhereIs{"10.0.20.0/24"} = "Datacenter, Second Floor";
      $WhereIs{"10.0.30.0/27"} = "Remote location";
      $WhereIs{"0.0.0.0/0"} = "God knows where";

      foreach $host ("10.0.10.1", "10.0.20.15", "10.0.32.17", "10.10.0.1") {
         print "Host $host is in ", $WhereIs{$host}, "\n";
      }

      foreach $subnet (keys %WhereIs) {
         print "Network ", $subnet, " is used in ", 
         $WhereIs{$subnet}, "\n";
      }

      untie %WhereIs;

DESCRIPTION
    This module overloads hashes so that the key can be a subnet as in
    NetAddr::IP. When looking values up, an interpretation will be made to
    find the given key within the subnets specified in the hash.

    The code sample provided on the SYNOPSIS would print out the locations
    of every machine in the `foreach' loop.

    Care must be taken, as only strings that can be parsed as an IP address
    by NetAddr::IP can be used as keys for this hash.

    Iterators on the hash such as `foreach', `each', `keys' and `values'
    will only see the actual subnets provided as keys to the hash. When
    looking up a value such as in `$hash{$ipaddress}' this IP address will
    be looked up among the subnets existing as keys within the hash. The
    matching subnet with the longest mask (ie, the most specific subnet)
    will win and its associated value will be returned.

    This code can be distributed freely according to the terms set forth in
    the PERL license provided that proper credit is maintained. Please send
    bug reports and feedback to the author for further improvement.

AUTHOR
    Luis E. Munoz (lem@cantv.net)

SEE ALSO
    perl(1), NetAddr::IP(3).