my %server_hash = ( foo => {tag => 1},
                    bar => {tag => 10},
                    boot => {tag => 2},
                    snow => {tag => 8},
                    fish => {tag => 3},
                    adv => {tag => 1}
                   );

foreach my $server ( sort {$server_hash{$a} cmp 
                              $server_hash{$b}
                        && $server_hash{$a}{tag} <=>  
                              $server_hash{$b}{tag}
                           } keys %server_hash)
{
        print "$server:$server_hash{$server}{tag}\n";
}

##</code><code>##

foo:1
adv:1
boot:2
fish:3
snow:8
bar:10