SNMP Simple description and installation

SNMP (Simple network Management Protocol) simplified Web Management Protocol

SNMP is an application-layer protocol that is part of the TCP/IP protocol family. It makes it easy to Exchange management information between network devices. Enables network administrators to manage network performance, discover and solve network problems, and expand networks.

There are three versions of SNMP Snmpv1,snmpv2,snmpv3

SNMPV1: All security mechanisms are based on communities to achieve

Notification of three mechanisms:

Read-only

Read-write

Trap

The default communities

Public: Read-only

Private: Read-write

MIB: (Management information Base) management Information base

Standard MIB Library: mib-ii

What is the MIB?

MIB is the corresponding library of device name and device number

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Example: the number (OID) of an interface for each object device may be represented as shown in

Ckl.company.linuxSer1.if0

The corresponding device OID:

1.6.3.1

Device number:

OID and device establish a correspondence relationship

Objects that can be monitored:

Fault Management: Fault Management

Configuration Management: Configure management, can configure the management of Things

Accounting Management: Account Management, login user management

Performance Management: Performance management, monitoring server performance.

Security Management: Safety Management

About ports:

By default, the monitor side opens: 161 Port, UDP.

The monitor side only opens 162 ports when a trap is required, UDP

Default mid library, name corresponding OID

system:1.3.6.1.2.1.1

Defines a list of system objects, including system run time, System contact, system name

interfac:1.3.6.1.2.1.2

Define the status information of the interface, send packets, accept packets, and so on.

at:1.3.6.1.2.1.3

Defining NAT-related routing information

ip:1.3.6.1.2.1.4

Define IP-related information, IP routing, etc.

icmp:1.3.6.1.2.1.5

Defining ICMP-related information, errors, discards, etc.

tcp:1.3.6.1.2.1.6

Define TCP connection Status, Listing,establish, closed, etc.

udp:1.3.6.1.2.1.7

Defining the status of UDP

egp:1.3.6.1.2.1.4

transmission:1.3.6.1.2.1.4

snmp:1.3.6.1.2.1.4

SNMP operations

Get: Get information about a port that corresponds to a specific node

GetNext: Obtaining information for the corresponding node

Getbulk: Perhaps the information in a domain

Set: The control command will be initiated

GetResponse: Get the response information, the client came to the

Trap

Notification

Inform

Report

SNMP Installation

installed by the monitored side: net-snmp

Monitor-side installation: Net-snmp-utils, NET-SNMP (required only if trap is required)

1. Installation

# yum Install Net-snmp net-snmp-utils

2. Start the service

#/ETC/INIT.D/SNMPD Start

3. Execute command to get information

# snmpwalk-v 2c-c public localhost

-v Specifies the version number

-C Specify Communities

LocalHost Monitoring object

SNMP enabled by default two MIB libraries get information Snmpv2-mib, Host-resources-mib

To view information about a resource:

# snmpget-v 2c-c public localhost host-resources-mib::hrsystemuptime.0

4. View TCP connection status information

View information about the MIB library for TCP

#cd/usr/share/snmp/mibs

# more Tcp-mib.txt

....

TCP OBJECT IDENTIFIER:: = {mib-2 6}

....

The OID number of the MIB that is viewed to TCP is 6

Adding configuration information about TCP in the configuration file

View SystemView included. 1.3.6.1.2.1.6

Restart Service

#/ETC/INIT.D/SNMPD Restart

Viewing TCP connection Information

# snmpwalk-v 2c-c public localhost tcp

View the number of connection states

# snmpwalk-v 2c-c public localhost tcp | grep Establish | Wc-l

2

5. Modify Communities

# vi/etc/snmp/snmpd.conf

....

#com2sec notconfiguser Default Public #默认

Com2sec notconfiguser 192.168.1.0 Cklworld #修改后

Restart Service:

#/ETC/INIT.D/SNMPD Restart

Test whether the default can get information:

# snmpwalk-v 2c-c public 192.168.1.189 TCP get failed

Get information using the new communities:

# snmpwalk-v 2c-c cklworld 192.168.1.189 TCP

Snmpstatus usage:

# snmpstatus-v 2c-c Cklworld 192.168.1.189

[UDP: [192.168.1.189]:161->[0.0.0.0]]=>[linux ckl 2.6.32-504.23.4.el6.x86_64 #1 SMP Tue June 9 20:57:37 UTC 201 5 x86_64] up:1:52:35.85

interfaces:0, Recv/trans packets:0/0 | ip:0/0

This article is from the "OPS rookie" blog, please be sure to keep this source http://ckl893.blog.51cto.com/8827818/1683323

SNMP Simple description and installation