Solstice Enterprise Manager 4.1 Customizing Guide

Chapter 9

SNMP Management

Simple Network Management Protocol (SNMP) is a protocol for exchanging information between network managers and agents processes within various managed objects that are able to report their status on request. It is a connection-less protocol, with the view of continuing to receive information from managed objects even when network performance is degraded and a connection-based reliable transport may fail.

This chapter describes the following topics:

• Section 9.1 SNMP Managed Components
• Section 9.2 SNMP Management Protocol Adapter
• Section 9.3 SNMP MPA Configuration
• Section 9.4 Specifying the Version of SNMP Used

9.1 SNMP Managed Components

Solstice Enterprise Manager (Solstice EM) provides the following components for management of network resources that are manageable using SNMPv1 and SNMPv2c:

• An SNMP daemon (snmpd) which can be installed on Sun workstations.

  For information about the SNMP daemon refer to the Site/SunNet/Domain Manager Reference Manual. Procedures for installing the SNMP daemon is available in Chapter 6 of Installation Guide

• Distributable SNMP proxy agents (na.snmp and na.snmpv2) that use Remote Procedure Call (RPC) protocol to handle communication (such as threshold-checking) between the Solstice EM management station (where the MIS resides) and SNMP agents.

  The RPC-based SNMP proxy agents are described in Chapter 10.

• A distributable SNMP trap daemon (em_snmp-trap) which listens for SNMP event notifications (traps) and translates these into CMIP event notifications for forwarding to the Solstice EM MIS. The trap daemon can also be configured to forward unprocessed SNMP traps to other managers.

  The SNMP trap daemon is discussed in Chapter 11.

FIGURE 9-1   Components of Solstice EM's SNMP Management Support

• A distributable SNMP Management Protocol Adaptor (MPA), which handles communication of management requests and agent responses between the Solstice EM MIS and SNMP agents.

9.2 SNMP Management Protocol Adapter

The Simple Network Management Protocol (SNMP) Management Protocol Adapter (MPA) allows for the retrieval of data and the setting of attribute values for SNMP managed devices. The SNMP MPA works as a proxy agent between the Solstice EM MIS and any device on the network which is SNMP-manageable. The proxy agent allows you to manage any number of Management Information Bases (MIBs), where either standard SNMP MIB objects or enterprise-specific objects can be defined. SNMP MIBs get compiled by the Concise MIB compiler (em_cmib2gdmo) into GDMO and ASN.1 descriptions which then get loaded into the Solstice EM MIS.

The SNMP MPA processes Common Management Information Service (CMIS)-like requests received from the MIS, translates them into SNMP requests, and sends the requests out to the intended device. The translation is based on the OMNIPoint I Internet-ISO Management Coexistence (IIMC) standard. The SNMP MPA then receives the response from the SNMP device and forwards it back to the MIS.

9.3 SNMP MPA Configuration

The following configuration parameters for the SNMP MPA are set during installation:

• Default MIS host--The name of the machine running the MIS that the MPA is to connect to.
• Default MIS port--The port used in communicating with the MIS (by default this is port 5555).
• Default SNMP MPA port--The port on which the SNMP MPA listens for incoming messages (by default this is port 5575).
• SNMP request timeout--The length of time the SNMP MPA waits for a response to a request sent to an SNMP agent (by default, this is 20 seconds).
• SNMP retries--The number of times the SNMP MPA retries a request to an SNMP agent if there is no response (by default this is three).
  

  The request and retry parameters determine when the SNMP MPA determines that an SNMP agent is unavailable.

9.4 Specifying the Version of SNMP Used

Solstice EM supports the SNMPv1 and SNMPv2c protocols. When you are performing management operations on objects in an SNMP agent, you have to specify the version of SNMP used for communications between the SNMP agent and your application.

Specify the version of SNMP used in either of the following ways:

• Calling the set_management_protocol function of the EMSnmpAgent class
• Using the PMI to set the managementProtocol attribute

9.4.1 Calling the set_management_protocol Function of the EMSnmpAgent Class

Call the set_management_protocol function if you are using the EMSnmpAgent class to represent your SNMP agent. In the call to the set_management_protocol function, set the argument as follows depending on the version of SNMP:

• SNMPv1: EMSnmpAgent::snmp_v1
• SNMPv2c: EMSnmpAgent::snmp_v2

A call to the set_management_protocol function is shown in CODE EXAMPLE 9-1.

CODE EXAMPLE 9-1   Calling the set_management_protocol Function

... EMSnmpAgent::set_management_protocol (EMSnmpAgent::snmp_v2); ...

In this example, SNMPv2c is used for communications between the SNMP agent and the application.

9.4.2 Using the PMI to Set the managementProtocol Attribute

If you are using the Image class to represent your SNMP agent, set the managementProtocol attribute when you initialize the instance of Image. To set the managementProtocol attribute, call the set_str function. You must set the managementProtocol attribute to the object identifier (OID) of the version of SNMP that you are using.

The versions of SNMP are identified by the following OIDs:

• SNMPv1: 1.3.6.1.4.1.42.2.2.2.9.2.4.3.1
• SNMPv2c: 1.3.6.1.4.1.42.2.2.2.9.2.4.3.2

  CODE EXAMPLE 9-2 shows code for setting the managementProtocol attribute.

  CODE EXAMPLE 9-2   Setting the managementProtocol Attribute Directly 

  ... Image im; ... im.set_str ("managementProtocol","{1 3 6 1 4 1 42 2 2 2 9 2 4 3 1}"); ...

  In this example, SNMPv1 is used for communications between the SNMP agent and the application.