Snmp Protocol Version; Mib Overview; Snmp Configuration - 3Com MSR 50 Series Configuration Manual

2086 C 113: SNMP C
HAPTER

SNMP Protocol Version

MIB Overview

SNMP Configuration

ONFIGURATION
Get operation: NMS gets the value of a certain variable of Agent through this
■
operation.
Set operation: NMS can reconfigure certain values in the Agent MIB
■
(management information base) to make the Agent perform certain tasks by
means of this operation.
Trap operation: Agent sends Trap information to the NMS through this
■
operation.
Inform operation: NMS sends Trap information to other NMSs through this
■
operation.
Currently, SNMP agents support SNMPv3 and are compatible with SNMPv1 and
SNMPv2c.
SNMPv1 and SNMPv2c authenticate by means of community name, which defines
the relationship between an SNMP NMS and an SNMP Agent. SNMP packets with
community names that did not pass the authentication on the device will simply
be discarded. A community name performs a similar role as a key word and can be
used to regulate access from NMS to Agent.
SNMPv3 offers an authentication that is implemented with a User-Based Security
Model (USM for short), which could be authentication with privacy, authentication
without privacy, or no authentication no privacy. USM regulates the access from
NMS to Agent in a more efficient way.
Management information base (MIB) is a collection of all the objects managed by
NMS. It defines the set of characteristics associated with the managed objects,
such as the object identifier (OID), access right and data type of the objects.
MIB stores data using a tree structure. The node of the tree is the managed object
and can be uniquely identified by a path starting from the root node. As illustrated
in the following figure, the managed object B can be uniquely identified by a
string of numbers {1.2.1.1}. This string of numbers is the OID of the managed
object B.
Figure 624 MIB tree
1
1
1
1
B
5
A
As configurations for SNMPv3 differ substantially from those of SNMPv1 and
SNMPv2c, their SNMP functionalities will be introduced separately below.
Follow these steps to configure SNMPv3:
2
2
2
6