The application of SNMP in Enterprise network

Snmp,simple Network Management Protocol: A Simple Network management protocol, which is a standard protocol for managing nodes on an IP network. This protocol includes a set of monitoring and control variables and two data formats for monitoring devices: SMI and MIB.

Using SNMP for network management requires several important components: Management base station, management agent, management information base and network management tools. The management base station is usually a stand-alone device, which serves as a user interface for network management. The base station must be equipped with the management software, the user interface that the administrator can use and the database that obtains the information from the MIB, and it should have the ability to send the management commands to the base station for network management.

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 that provides only the most basic set of features, especially for small, fast, and low price environments. The implementation of SNMP is based on connectionless Transport layer protocol UDP, so it can realize the barrier-free connection with many products

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 network management platform has Quidview, Sun Netmanager and IBM NetView.

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

The NMS can send Getrequest, getnextrequest and setrequest messages to the agent, and after receiving these request messages from the NMS, the agent will read or write according to the message type and generate the response message. and return the message 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.

Let's look at a case to illustrate the configuration of SNMP:

Suppose a company's workstation is a host of IP 192.168.5.100, now let this machine to monitor and manage the company's network, the company's network includes two routers and a switch, the simple figure is as follows:

Detailed configuration is as follows:

Configuration of Switch SW1:

[Sw1]int vlan-interface 1 configuration Management Vlan address;

[Sw1-vlan-interface1]ip Add 192.168.5.200 255.255.255.0

[Sw1-vlan-interface1]quit

[Sw1]ip route-static 0.0.0.0 0.0.0.0 192.168.5.1 Configure the default route;

[Sw1]snmp-agent starts the SNMP service;

[Sw1]snmp sys-info Contact Xiaoming set up the contacts for this device;

[Sw1]snmp-agent sys-info location Beijing set the corresponding address of the device;

[Sw1]snmp-agent sys-info version all set SNMP versions, here are all versions supported

[Sw1]snmp-agent Community Read public sets the read-only permission key;

[Sw1]snmp-agent Community write private to set the writable permission key;

[Sw1]snmp-agent Trap Enable allows trap information to be sent;

[Sw1]snmp-agent target-host trap address udp-domain 192.168.5.100 params securityname public

Address and corresponding key sent to the target host;

Router rbeijing configuration:

[Router] int S0

[Beijing-serial0]ip Add 192.168.4.2 24 configuration serial0 address;;

[Beijing-serial0]shut

[Beijing-serial0]undo shut serial The best to restart;

[Router-serial0]quit

[Beijing]int eth1

[Beijing-ethernet1]ip Add 192.168.5.1 24 configuration eth1 address;

[Beijing-ethernet1]quit

[Router]sysname Beijing give this router a name;

[Beijing]ip route-static 192.168.2.0 24 192.168.4.1 Configure the default route;

[Beijing]snmp-agent Community Read public sets a read-only key;

[Beijing]snmp-agent Community write private to set a writable key;

[Beijing]snmp-agent sys-info contact Xiaoliang this device;

[Beijing]snmp-agent sys-info location Beijing The corresponding address of the equipment;

[Beijing]snmp-agent sys-info version all settings support all versions of SNMP;

[Beijing]snmp-agent Trap enable to open SNMP trap function;

[Beijing]snmp-agent target-host Trap address 192.168.5.100 SECU The key that is sent to the target host