for my $test (@testlist) {
    if (defined $tref->{$host}{$test}) {
        my $status = $tref->{$host}{$test}{status};
        my $duration = $tref->{$host}{$test}{dur};
        # debugging line
        if (!$tref->{$host}{$test}{status}) { print "$host=>$test\n";}

        # Some more processing here which is not relevent
    }
    else {
        print "\t<th>-</th>\n";
   }
}

##</code><code>##

 'vnsgnnwwor-gw-1' => {
                         'conn' => {
                                     'dur' => '2.09 hours',
                                     'status' => 'red'
                                   },
                         'mrtg' => {
                                     'dur' => '4.00 hours',
                                     'status' => 'green'
                                   }
                       },

##</code><code>##

#!/usr/bin/perl -l
use strict;
use warnings;

my $tref = {
    'vnsgnnwwor-gw-1' => {
        'conn' => {
            'dur' => '2.09 hours',
            'status' => 'red'
        },
        'mrtg' => {
            'dur' => '4.00 hours',
            'status' => 'green',
        },
    },
    };

my $host = 'vnsgnnwwor-gw-1';
my $test = 'http';

print "$host is ", defined $tref->{$host} ? "True" : "False";
print "$test is ", defined $tref->{$host}{$test} ? "True" : "False";
print "$test=>status is ", defined $tref->{$host}{$test}{status} ? "True" : "False";
print "$test is ", defined $tref->{$host}{$test} ? "True" : "False";

##</code><code>##

vnsgnnwwor-gw-1 is True
http is False
http=>status is False
http is True