What additional steps must be taken when configuring SNMPv3 compared to SNMPv2?

When configuring SNMPv3, entering a username is a crucial step that is not required in SNMPv2. This addition reflects the enhanced security features found in SNMPv3, which incorporates user-based access control alongside encryption and authentication protocols to safeguard the management information. In SNMPv2, the process mainly involved setting community strings for access control, which does not offer the same level of security.

The introduction of a username in SNMPv3 allows for finer control over access to the SNMP agent, enabling different permissions for different users. This is particularly important in environments where network security is paramount.

The other choices do not add to the understanding of the configuration differences: enabling Public Mode is specific to community strings in SNMPv2, no additional steps would be inaccurate as configuring SNMPv3 does require more initial setup, and there is typically no need to reboot the device after configuring SNMP settings, as they often take effect immediately.