I don't see anything obviously wrong, though it looks odd to be using a device name as a host name. Is that really what you intend?

You might gain some insight by trying to come up with a small example that demonstrates the problem. Something like

  use strict;
  use Net::SNMP;
  my $version = ".1.3.6.1.2.1.1.1.0";
  my %snmp_options = ( ... };
  $s = NET::SNMP->session(\%snmp_options);
  print $s->get_request($version);
  $s->close();
[download]

and then explicitly fill in %snmp_options.

This approach strips out extraneous detail, and should help you isolate the problem quickly.