It's not immediately obvious what the origin of this message is from the Net::SNMP source, normally I wouldn't expect EPERM from simply try to create a UDP socket, but as you don't say what your OS is I can't be sure. You might want to get more diagnostic information by adding -debug => 0x04, to the arguments to session(). Also can you confirm whether the program works properly from the command line or not.

/J\