next unless $item->{is_a_switch};

##</code><code>##

#!/usr/local/bin/perl

use strict;
use warnings;

my %network = get_network();

for my $blade (keys %network){
  
  for my $item (@{$network{$blade}}){
    next unless $item->{is_a_switch};
    print qq{$item->{item_name}\n};
    
    for my $kit (@{$item->{more_kit}}){
      print qq{  kit: $kit->{kit_name}\n};
    }
    
  }
  
}

sub get_network {
  my %network = (
    01/01 => [
      {
        is_a_switch => 0,
        item_name   => q{router},
        more_kit    => 0,
      },
      {
        is_a_switch => 1,
        item_name   => q{hpswitch1},
        more_kit    => [
          {
            port      => q{port1},
            kit_name  => q{workstation1},
          },
          {
            port      => q{port2},
            kit_name  => q{workstation2},
          },
        ],
      }
    ],
    01/02 => [
      {
        is_a_switch => 1,
        item_name => q{hpswitch2},
        more_kit  => [
          {
            port      => q{port1},
            kit_name  => q{server4},
          },
          {
            port      => q{port2},
            kit_name  => q{server5},
          },
        ],
      }
    ],
    01/03 => [
      {
        is_a_switch => 0,
        item_name   => q{server2},
        more_kit  => 0,
      },
    ],
  );
  return %network;
}

##</code><code>##

hpswitch1
  kit: workstation1
  kit: workstation2
hpswitch2
  kit: server4
  kit: server5