#!/usr/local/bin/perl -w
use strict;

use Data::Dumper;

my %old_hash =
(
    '1.1.1.1'  => 'nfs,1',
    '4.4.4.4'  => 'cifs,0',
    '10.0.4.2' => 'afp,1',
    '3.3.3.3'  => 'nfs,0',
    '5.5.5.5'  => 'afp,0',
);

my %new_hash =
(
    '1.1.1.1'   => 'nfs,0',     # index change
    '200.4.4.4' => 'cifs,0',    # IP change
    '200.0.4.2' => 'afp,1',     # IP change
    '3.3.3.3'   => 'nfs,1',     # index change
    '5.5.5.5'   => 'afp,0',
    '4.22.2.22' => 'afp,2',     # new entry
);

my %changes;

foreach my $key ( keys %new_hash )
{
    $changes{$key} = $new_hash{$key} 
        unless ( (exists $old_hash{$key}) && $new_hash{$key} eq $old_hash{$key} );
    # gotta check for existence to quiet warnings.
}


print Dumper( \%changes );