Practical Network monitoring: Snmp+what ' s up gold

In this blog to chat with readers to talk about how to use the SNMP protocol and accessibility tools what ' s up gold to help monitor network devices, which is very efficient to help network administrators to understand the status of the device, then first introduce the SNMP protocol.

1.1. SNMP Introduction

At present, the most widely used network management protocol in the network is SNMP (Simple network Management

Protocol, Simple Network Management Protocol). SNMP is widely accepted and put into use industrial standards, to ensure that the management information in the network at any two points between the transmission, easy to network administrators in any node on the network to retrieve information, modify information, locate the fault, complete the fault diagnosis, capacity planning and generate reports.

SNMP employs a polling mechanism (shown here in what's up Gold software), providing only the most basic feature sets, especially for small, fast, and low price

Use in the environment. The implementation of SNMP is based on connectionless transport-layer protocol UDP (Agent 161, Trap 162), which enables accessibility to many products.

1.2. The working mechanism of SNMP

SNMP is divided into NMS and Agent two parts:

NMS (Network Management station, network Management station) is the workstation that runs the client program, the current commonly used management platform is Quidview, Sun Netmanager and IBM NetView, but these can be charged, Small weave here to find a free what ' up gold.

An Agent is a server-side software running on a network device.

NMS can send Getrequest, getnextrequest and setrequest packets to the agent, after receiving these request messages from NMS, the Read or Write operation is generated according to the message type, the response message is produced and The message is returned to the NMS.

The Agent will also proactively send Trap packets to the NMS and report to the NMS the events that occur when the device is in an abnormal condition or the state changes, such as when the device restarts.

1.3, the SNMP version

Currently, the SNMP Agent in the device supports the SNMP V3 version, the compatible SNMP V1 version, and the SNMP v2c version.

The SNMP v3 adopts user name and password authentication method.

SNMP v1, SNMP v2c, with community name (Community name) authentication, SNMP packets that are not device-approved community names are discarded.

The SNMP community name is used to define the relationship between SNMP NMS and the SNMP Agent. The community name acts like a password, restricting SNMP NMS access to SNMP agents on the device. The user can optionally specify one or more of the following attributes associated with the group name:

A, defines the MIB view that the community name can access.

b, set the group name access to the MIB object is read or write permission (write) or read-only permission (read). A community name with read-only access can only query the device information, and a community name with read and write permissions may also configure the device.

C, set the basic access control list specified by the community name.

2, configure the basic functions of SNMP

The configuration of the SNMP V3 version and the SNMP V1 version, the SNMP v2c version, is significantly different and is described in two cases when configuring the basic functions of SNMP. V1, v2c specific configuration see figure 2-1, 2-2

Figure 2-1