The proxySG currently only supports the standard AES128 encryption method for SNMP.
When configuring SNMP on the ProxySG, there is an option to use AES encryption, as shown below:
Some SNMP vendors may require you to select a specific version of AES (e.g AES192, AES128 or AES256). When selecting "AES" on the ProxySG, you should select "AES128" on your SNMP receiving software.