#!/usr/bin/env perl
use strict;
use warnings;
use XML::Twig;

my $t = XML::Twig->new( 
  twig_handlers => {
    'ip4-network' => \&network,
  },      
  pretty_print => 'indented', 
);

my $xml = do{local $/;<DATA>};
$t->parse($xml);

sub network {
  my ($t,$e) = @_;
  my $range = $e->first_child('dhcp-range');
  if ( defined $range ){
    # do stuff
    print $range->att('range')."\n";
  };
}