If you're not completely locked in to your input parameters, Getopt::Long may be useful to you.

use strict;
use warnings;
use Getopt::Long;

my %opts;

GetOptions(
  'address=s' => sub { $opts{$_[0]} = $_[1]; }
  'user=s' => sub { $opts{$_[0]} = $_[1]; }
  'pass=s' => sub { $opts{$_[0]} = $_[1]; }
  'protocol=s' => sub { $opts{$_[0]} = $_[1]; }
  'snmp_community=s' => sub { $opts{$_[0]} = $_[1]; }
  'snmp_port=s' => sub { $opts{$_[0]} = $_[1]; }
  'snmp_timeout=s' => sub { $opts{$_[0]} = $_[1]; }
  ...
}
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Getopt::Long can be set to carp/croak when your script doesn't have all the required items, which may come in handy as well.