What is an advantage of using SNMP v3 instead of SNMP v1/v2 when querying a FortiGate unit?

Using SNMP v3 provides the benefit of packet encryption, which greatly enhances the security of the information being transmitted between the FortiGate unit and the managing system. Unlike SNMP v1 and v2, which do not offer any form of encryption, SNMP v3 introduces confidentiality features, allowing sensitive data exchanged over the network to be encrypted. This makes it significantly more secure against eavesdropping, man-in-the-middle attacks, and other security threats which are common in unmanaged networks.

Encryption helps protect not just the integrity of the SNMP messages but also the sensitivity of the network management information being accessed and controlled. This is particularly important in enterprise environments where the risk of data interception and manipulation could have serious repercussions.

The other options, while they may present certain operational advantages, do not specifically address the key enhancement that SNMP v3 brings to the table regarding security. For instance, MIB-based report uploads, access list limitations, and running the service on a non-standard port are features present in various versions of SNMP but do not inherently contribute the same level of security against unauthorized access as packet encryption does.