ZyXEL Communications ZyXEL Dimension GS-3012F - Manual (Page 122)

GS-3012F User’s Guide
17-2 Access Control
17.3 About SNMP
Simple Network Management Protocol is a protocol used for exchanging management information between
network switches. SNMP is a member of TCP/IP protocol suite. A manager station can manage and monitor the
GS-3012F through the network via SNMP version one (SNMPv1) and/or SNMP version 2c. The next figure
illustrates an SNMP management operation. SNMP is only available if TCP/IP is configured.
Figure 17-3 SNMP Management Model
An SNMP managed network consists of two main components: agents and a manager.
An agent is a management software module that resides in a managed switch (the GS-3012F). An agent translates
the local management information from the managed switch into a form compatible with SNMP. The manager is
the console through which network administrators perform network management functions. It executes applications
that control and monitor managed devices.
The managed devices contain object variables/managed objects that define each piece of information to be collected
about a switch. Examples of variables include such as number of packets received, node port status etc. A
Management Information Base (MIB) is a collection of managed objects. SNMP allows a manager and agents to
communicate for the purpose of accessing these objects.
SNMP itself is a simple request/response protocol based on the manager/agent model. The manager issues a request
and the agent returns responses using the following protocol operations:
Table 17-2 SNMP Commands
COMMAND DESCRIPTION
Get Allows the manager to retrieve an object variable from the agent.
GetNext Allows the manager to retrieve the next object variable from a table or list within an agent. In
SNMPv1, when a manager wants to retrieve all elements of a table from an agent, it initiates a
Get operation, followed by a series of GetNext operations.