SNMPv1 and SNMPv2c do not provide security, authentication, or encryption. Without authentication, a non authorized user could perform SNMP network management functions and eavesdrop on management information as it passes from system to system. Many SNMPv1 and SNMPv2c implementations are restricted read-only access, which, in turn, reduces the effectiveness of a network monitor in which network control applications cannot be supported.
To implement SNMPv3, an authentication and encryption method must be assigned to a user to be validated by the device. SNMP authentication allows the router to validate the managing node that issued the SNMP message and determine whether the message was tampered with.
The following figure shows the configuration requirements to implement SNMPv1/SNMPv2c, and SNMPv3.
