C H A P T E R  6

Using Simple Network Management Protocol (SNMP)

This chapter describes how to use SNMP. This chapter includes the following sections

SNMP Overview

The server supports the Simple Network Management Protocol (SNMP) interface, versions 1 and 2c. SNMP is an open technology that enables the management of networks and devices, or nodes, connected to the network. SNMP messages are sent over IP using the User Datagram Protocol (UDP). Any management application that supports SNMP can manage your server.

How SNMP Works

Utilizing SNMP requires two components, a network management station and a managed node (in this case, the system controller in your server). Network management stations host management applications, which monitor and control managed nodes.

Managed nodes are any number of devices, including servers, routers, and hubs, which host SNMP management agents responsible for carrying out the requests from management stations. The management station monitors nodes by polling management agents for the appropriate information using queries. Managed nodes can also provide unsolicited status information to a management station in the form of a trap. SNMP is the protocol used to communicate management information between the management stations and agents.

The SNMP agent is preinstalled and runs on the system controller, so all SNMP management of the server should occur through ALOM CMT. To utilize this feature, your operating system must have an SNMP client application. See your operating system vendor for more information.

The SNMP agent on your system controller provides the following capabilities: inventory management, and sensor and system state monitoring.

SNMP Management Information Base Files

The base component of an SNMP solution is the Management Information Base (MIB). A MIB is a text file that describes a managed node's available information and where it is stored. When a management station requests information from a managed node, the agent receives the request and retrieves the appropriate information from the MIBs. ALOM CMT supports the following SNMP classes of Management Information Base (MIB) files. Download and install the product-specific MIB files for your platform.

MIBs Integration

Use the MIBs to integrate the management and monitoring of the server into SNMP management consoles. The MIB branch is a private enterprise MIB, located at MIB object iso(1).org (3). dod (6). internet (1). private (4). enterprises (1). sun (42). products (2).

The standard SNMP port (161) is used by the SNMP agent on the system controller.

SNMP Messages

SNMP is a protocol, not an operating system, so you need some type of application to use SNMP messages. Your SNMP management software might provide this functionality, or you can use an open source tool like net-SNMP, which is available at:


Both management stations and agents use SNMP messages to communicate Management stations can send and receive information. Agents can respond to requests and send unsolicited messages in the form of a trap. There are five functions that management stations and agent use:

By default, port 161 is used for SNMP messages and port 162 is used to listen for SNMP traps.


The system controller has a preinstalled SNMP agent that supports trap delivery to an SNMP management application.

To use this feature, you must:

1. Integrate the platform-specific MIBs into your SNMP environment.

2. Enable SNMP in ALOM-CMT. By default, SNMP is disabled in ALOM CMT.

3. Tell your management station about your server.

4. Configure the specific traps.

Integrating the MIBs

Load the ENTITY-MIB and the SUN-PLATFORM-MIB into your SNMP management application.

Adding Your Server to Your SNMP Environment

Add your your server as a managed node using your SNMP management application. The read-only community string for ALOM CMT is set to public and cannot be modified. ALOM CMT does not allow write access using SNMP sets.

See your SNMP management application documentation for further details.

Configuring Receipt of SNMP Traps

To configure traps in ALOM CMT, see mgt_snmptraps and mgt_traphost.

Traps will be sent with the community string of public.