Examining The Mib Structure - Lucent Technologies PortMaster 4 Configuration Manual

Understanding SNMP
MIB Specification Overview
The PortMaster 4 MIB conforms to the first version of the Structure of Management
Information (SMIv1) (RFCs 1212 and 1213). The private MIB for the product describes
the data for configuration, fault, performance, security, and accounting management.
• Chassis MIB
• Configuration management (equipment, physical interfaces, and logical interfaces)
• Fault management (fault detection and fault isolation traps)
• Performance management (interfaces)
• Security management (MIB access control)
• Administration management (read-write community and trap community)
PortMaster products also support MIB II objects, and the enterprise-specific traps
provide information about several alarm conditions that can be enabled or disabled. The
traps are generated as SNMPv1 traps.
The PortMaster 4 SNMP agent consists of a multilingual master agent (supporting
SNMPv1, v2, and v3 protocols) and subagents with AgentX interfaces with the master
agent to handle different subtrees in the MIB. The master agent listens on UDP port 161
for SNMP protocol data units (PDUs). The master agent processes the PDUs and
forwards them to appropriate subagents. The subgents are responsible for processing the
data. The master agent and the subagents can operate asynchronously. The subagents in
the SNMP software can dynamically register and unregister to provide and deny access
to portions of the MIB.
The MIB module LE41 specifies the first revision of the private MIB for the
PortMaster 4. It includes only the physical equipment—chassis, T1, E1, and T3 lines;
modems; serial ports; and Ethernet interfaces.
The livingston.mib file is in the SNMP directory of the ComOS software, and on the
World Wide Web at
http://www.livingston.com/marketing/products/pmtempl.html.

Examining the MIB Structure

The entire Management Information Base (MIB) hierarchy can be represented by a tree
structure. In this representation, the unnamed "root" of the tree divides into the
following main branches:
• Consultative Committee for International Telegraph and Telephone (CCITT)
• International Organization for Standardization (ISO)
• ISO/CCITT
Each branch and subbranch in the tree structure is known as an object, and each object
is represented by an object name and an object identifier (OID). Figure 3-1 traces
the "path" from the ISO branch of the MIB to the Livingston MIB.
3-2 PortMaster 4 Configuration Guide