Final answer:
Two features supported by SNMPv3 that are not found in SNMPv1 or SNMPv2c are message integrity, ensuring data hasn't been altered, and authentication and encryption, which verify the source and protect the data from unauthorized access.
Step-by-step explanation:
The question pertains to the features of Simple Network Management Protocol (SNMP) and specifically what features are supported by SNMPv3 that are not in SNMPv1 or SNMPv2c. Two main features that are new with SNMPv3 are message integrity and authentication and encryption for security purposes.
Message integrity ensures that a packet has not been tampered with in transit. SNMPv3 provides a way of checking that the data has not been altered, whereas SNMPv1 and SNMPv2c lack this functionality. Additionally, SNMPv3 introduces authentication and encryption. Authentication verifies that the message is from a legitimate source and encryption makes the message unreadable to unauthorized users. SNMPv1 and SNMPv2c do not offer these comprehensive security measures, making SNMPv3 more secure for network management.