Snmp Engine Id - Cisco 300 Series Administration Manual

SNMP

SNMP Engine ID

SNMP Engine ID
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CAUTION
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Cisco Small Business 200, 300 and 500 Series Managed Switch Administration Guide (Internal Version)
The private Object IDs are placed under:
enterprises(1).cisco(9).otherEnterprises(6).ciscosb(1).switch001(101).
The Engine ID is used by SNMPv3 entities to uniquely identify them. 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. The default SNMP Engine ID is comprised of the enterprise number
and the default MAC address. This engine ID must be unique for the administrative
domain, so that no two devices in a network have the same engine ID.
Local information is stored in four MIB variables that are read-only (snmpEngineId,
snmpEngineBoots, snmpEngineTime, and snmpEngineMaxMessageSize).
When the engine ID is changed, all configured users and groups are erased.
To define the SNMP engine ID:
Click SNMP > Engine ID.
Choose which to use for Local Engine ID.
• Use Default—Select to use the device-generated engine ID. The default
engine ID is based on the device MAC address, and is defined per standard
as:
- First 4 octets—First bit = 1, the rest is the IANA enterprise number.
- Fifth octet—Set to 3 to indicate the MAC address that follows.
- Last 6 octets—MAC address of the device.
• None—No engine ID is used.
• User Defined—Enter the local device engine ID. The field value is a
hexadecimal string (range: 10 - 64). Each byte in the hexadecimal character
strings is represented by two hexadecimal digits.
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