I don't know how you populate your hash, but you wouldn't need to sort at all if you used an array instead:
my @SRV = (
'zumen530n.pdg.duranto.com',
'zumen531n.pdg.duranto.com',
'zumen532n.pdg.duranto.com', # etc
);
print "$_ $SRV[ $_ ]\n" for 0 .. $#SRV;
Of course, this prints 0-20 instead of 1-21, but that's easy to fix if it's important.
Update: In fact, whenever I see a hash like:
my %h = (
1 => 'foo',
2 => 'bar',
3 => 'baz',
4 => 'quux',
);
I always consider whether it wouldn't be better to use a simple array.