Hi fingers,
First off - good job for using Net::Snmp!   I used UCD SNMP for a similar script because of the included additional utilities, but in hindsight wish I'd done like you.

A couple of trivial suggestions come to mind:

• Getopt::Long might simplify processing of command-line arguments.
• If you're going to use $hostname instead of $_ in

  foreach(@hostname){
      undef @unique;
      $hostname=$_;
  [download]

  it could be a tiny bit cleaner as

  foreach $hostname(@hostname){
      undef @unique;
  [download]

• I don't know how well the particular syntax would transfer to your code, but "(code) mind your snmPs & Qs" uses a hash to count non-port interfaces, then subtracts them from final port status report.   As you note, it reaaally improves accuracy of generated reports.

BTW, thanks for the compliment in your pod.   I "appreciate poorly written code" because I'm so well practiced at *writing* it! 8^D
    cheers,
    Don
    striving toward Perl Adept
    (it's pronounced "why-bick")