The SNMP state dictionary

The SNMP state dictionary is based on RFC 1213 - Management Information Base for Network Management of TCP/IP-based internets - MIB-II. This document defines a management information base, which is organized in nine groups:

System Provides general information about the managed system.

Interfaces Provides generic information about the physical interfaces of the entity, including configuration information and statistics on the events occurring at each interface.

IP Contains information relevant to the implementation and operation of IP at a node.

ICMP Contains information relevant to the implementation and operation of ICMP at a node.

TCP Contains information relevant to the implementation and operation of TCP at a node.

UDP Contains information relevant to the implementation and operation of UDP at a node.

EGP Contains information relevant to the implementation and operation of EGP at a node;

Transmission Contains objects that provide details about the underlying transmission medium for each interface on a system;

SNMP Contains information relevant to the implementation and operation of SNMP.

In the SNMP State Dictionary, the primary state is based on the valid combinations of the Administrative and Operational Status, as they are defined in the Interfaces Group. This primary state holds one of the following values:

Down Administrative Status is Down/Operational Status is Down

Testing Administrative Status is Testing/Operational Status is Testing

Failed Administrative Status is Up/Operational Status is Down

Shutdown Administrative Status is Down/Operational Status is Up

You can extend this primary state to take into account your own state definitions and their associated representations. More information on extensions is provided in Customizing object states.

For visuals, see Graphical representation of SNMP primary states.

The SNMP State Dictionary also includes numerous secondary states. The secondary states are divided according to the group where they are referenced in MIB-II.

Most of the variables defined in MIB-II are counters, holding a numeric value ranging from 0 to 232-1. The valid interval for the SNMP secondary numeric states can be configured, using the IltLimitedNumericState API. The graphic representation of each state can be configured as a Gauge, Counter or Chart.

The valid interval for the SNMP secondary numeric states can be configured, as shown in this code extract:

IltSNMP.Interface.InDiscards.setMaxValue (new Float (100.0));

For visuals, see Graphical representation of SNMP secondary states.

For information on how to customize SNMP states, refer to Customizing the SNMP state system.

As well as defining the secondary states, which are represented graphically as gauges or charts, MIB-II also defines a group called System. This group is responsible for storing general information (such as location, contact person, and description) about the object being managed.

In the SNMP State Dictionary, this group is represented by a set of attributes. The attributes present in an object are mapped graphically to a window called System window. (See System window.)

Attributes can be added to the System Group and represented in the System window with their values. More information on this extension is provided in Creating a new attribute in the System group.