SNMP Engine ID

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).

CAUTION

When the engine ID is changed, all configured users and groups are erased.

To define the SNMP engine ID:

1. Click SNMP > Engine ID.
2. 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.

All remote engine IDs and their IP addresses are displayed in the Remote Engine ID table.

3. Click Apply. The Running Configuration file is updated.

The Remote Engine ID table shows the mapping between IP addresses of the engine and Engine ID. To add the IP address of an engine ID:

4. Click Add. Enter the following fields:
• Server Definition—Select whether to specify the Engine ID server by IP address or name.
• IP Version—Select the supported IP format.
• IPv6 Address Type—Select the IPv6 address type (if IPv6 is used). The options are:
• Link Local—The IPv6 address uniquely identifies hosts on a single network link. A link local address has a prefix of FE80, is not routable, and can be used for communication only on the local network. Only one link local address is supported. If a link local address exists on the interface, this entry replaces the address in the configuration.
• Global—The IPv6 address is a global Unicast IPV6 type that is visible and reachable from other networks.
• Link Local Interface—Select the link local interface (if IPv6 Address Type Link Local is selected) from the list.
• Server IP Address/Name—Enter the IP address or domain name of the log server.
• Engine ID—Enter the Engine ID.
5. Click Apply. The Running Configuration file is updated.