Not sure which part you are puzzling over. Simplistically: 
use strict;
use warnings;

my $VAR1;

$VAR1 = {
  '127' => {
    'network' => '10.182.48.0/24',
    'VLAN' => '3509'
  },
  '32' => {
    'network' => '10.182.12.0/25',
    'VLAN' => '2121'
  },
  '90' => {
    'network' => '10.183.243.128/25',
    'VLAN' => '3494'
  }
};

sub custom {
    # $a and $b are keys
    my $anet = $VAR1->{$a}{network};
    my $bnet = $VAR1->{$b}{network};
    
    return $anet cmp $bnet;
}

my @result = sort custom keys %$VAR1;

[download]
However it would probably be better to use Net::IPAddress to convert the IP address to a 32-bit int, then use <=> to compare them, and compare the ports if the addresses are the same.

In reply to Re: Sorting Hash / Array by cdarke
in thread Sorting Hash / Array by nickt9999

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.