3com S7906E 설치 설명서

 

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Inform operation: The NMS sends traps to other NMSs through this operation. 

Currently, SNMP agents support SNMPv3 and are compatible with SNMPv1 and SNMPv2c. 

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SNMPv1 uses community names for authentication, 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 password to regulate access from the NMS to the agent. 

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SNMPv2c uses community names for authentication. Compatible with SNMPv1, it extends the 

functions of SNMPv1. SNMPv2c provides more operation modes such as GetBulk and 

InformRequest; it supports more data types such as Counter64 and provides various error codes, 

thus being able to distinguish errors in more detail. 

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SNMPv3 offers an authentication mechanism that is implemented based on the User-based 

Security Model (USM). You can set the authentication and privacy functions. The former is used to 

authenticate the validity of the sending end of the authentication packets, preventing access of 

unauthorized users; the latter is used to encrypt packets between the NMS and agents, preventing 

the packets from being intercepted. USM ensures a more secure communication between SNMP 

NMS and SNMP agent by authentication with privacy, authentication without privacy, or no 

authentication no privacy. 

Successful interaction between an NMS and the agents requires consistency of SNMP versions 

configured on them. You can configure multiple SNMP versions for an agent to interact with different 

NMSs. 

Any managed resource can be identified as an object, which is known as the managed object. 

Management Information Base (MIB) is a collection of all the managed objects. It defines the hierarchy 

of the objects and a set of characteristics associated with the managed objects, such as the object 

identifier (OID), access right and data type. Each agent has its own MIB. An NMS can read or write the 

managed objects in the MIB. The relationship between an NMS, agent and MIB is shown in 

Figure 1-1 Relationship between an NMS, agent and MIB 

 

 

MIB stores data using a tree structure. Each node of the tree represents a managed object that 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 is the OID of 

the managed object B.