Application of SNMP in enterprise network of Campus

Introduction to SNMP

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

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 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.

Version of SNMP

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.

Case topology:

Configuration information
Router R1

[Router]sys R1

[R1]int ETH 0

[R1-ethernet0]ip Add 192.168.100.254 24 "Configure the appropriate address information"

[R1-ethernet0]undo shut

[R1-ethernet0]int ETH 1

[R1-ethernet1]ip Add 192.168.2.254 24 "Configure the appropriate address information"

[R1-ethernet1]quit

[R1]ip Route 0.0.0.0 0.0.0.0 192.168.2.1 ' Configure default route '

[r1]snmp-agent start SNMP agent]

[R1]snmp-agent Community Read Public "the right to communicate is read-only, community name is public"

[R1]snmp-agent Community Write private "permission is readable and writable, community name is private"

[R1]snmp-agent sys-info cantact ZHANGC "Set up Contacts"

[R1]snmp-agent sys-info location xxxxx "Contact Address"

[R1]snmp-agent sys-info version All "supports multiple versions of SNMP"

[R1]snmp trap enable ' start trap '

[R1]snmp target-host Trap address 192.168.100.10 securityname Public "trap to server 192.168.100.10, negotiation key is public"