my($valid_ip, $valid_external);
foreach my $check (@IPs) {
  # clean it up
  $check =~ s/^\s*(.*?)\s*$/\1/;

  # skip if not a valid IP
  next unless is_ip($check);
  # overwrite with the last IP we saw that's valid
  $valid_ip = $check;

  # skip unless it's an external IP
  next if (not is_public_ip($check))
      or (is_loopback_ip($check))
      or ($check eq "41.79.21.90");
  # overwrite with the last valid IP that is external
  $valid_external = $check;
}
# choose last external IP if we found one, else last valid IP
my $ip = $valid_external // $valid_ip;