Reference Guide

Configuring System Information 139
– Privacy — SNMP frames can carry encrypted data.
These mechanisms can be combined to provide three levels of security:
–No security
– Authentication
– Authentication and Privacy. Note that for both authentication and
privacy to be enabled, two groups with the same name, one with
authentication and one with privacy, must be created.
A group is a label for a combination of attributes that determines whether
members have read, write, and/or notify privileges. Users can be associated
with a group. A group is operational only when it is associated with an
SNMP user.
Global Parameters
The Engine ID is used by SNMPv3 entities to uniquely identify themselves.
Both a remote and local Engine ID can be specified.
An SNMP agent is considered an authoritative SNMP engine. This means
that the agent responds to incoming messages (Get, GetNext, GetBulk, Set),
and sends trap messages to a manager. The agent's local information is
encapsulated in fields in the message.
Each SNMP agent maintains local information that is used in SNMPv3
message exchanges (not relevant for SNMPv1 or SNMPv2). The default
SNMP Engine ID is comprised of the enterprise number and the default
MAC address. The SNMP engine ID must be unique for the administrative
domain, so that no two devices in a network have the same engine ID.
The local information is stored in four read-only MIB variables:
snmpEngineId, snmpEngineBoots, snmpEngineTime, and
snmpEngineMaxMessageSize.