Knowledge is Power. He who gets wisdom loves his own soul; he who cherishes understanding prospers. (Proverbs 19:8)

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Knowledge is Power

He who gets wisdom loves his own

soul; he who cherishes understanding

prospers.

(2)

Monitoring Tool -MRTG

on CentOS 6.4

Jeong Chul

tland12.wordpress.com

www.youtube.com/user/tland12

Computer Science

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Monitoring Tool - MRTG

on CentOS 6.4

Part 1 Managed Devices

•

Chapter 1 Network Monitoring Structure

•

Chapter 2 Basic Terminology

•

Chapter 3 Testing Environment

•

Chapter 4 Managed Devices

•

Chapter 5 MRTG Configuration (1)

Part 2 NMS – MRTG

•

Chapter 5 MRTG Configuration (2)

•

Chapter 6 Email Notification

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Chapter 1 Network Monitoring Structure

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Chapter 2 Basic Terminology

1.SNMP - Simple Network Management Protocol

• an application-layer protocol that facilitates the exchange of management information

• works between a network management system (NMS), agents, and managed devices.

• uses TCP/IP protocol suite.

2. Agent

 A network-management software module that resides in a managed device such as

the Cisco IOS software

 has local knowledge of management information

 makes that information available by using SNMP.

3. NMS - Network Management System

 Run applications that monitor and control managed devices.

 provide resources required for network management.

 NMS applications such as MRTG, Cacti or Nagios.

4. Managed Device

 Contain an SNMP agent and reside on a managed network.

 Collect and store management information and make it available to NMS by using SNMP.

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Chapter 3 Testing Environment

1.NMS – MRTG (Multi Router Traffic Grapher)



IP Address: 192.168.80.6



OS: CentOS 6.4



Hostname: client.chul.com



Need to install and start MRTG service with Web server

2. Managed Devices

1)Linux Server – 192.168.80.5 (CentOS 6.4)



Need to install

net-snmp

package and start SNMPD

2)Windows Server 2008 - 192.168.80.48



Need to install snmp file and start SNMP service

3) Cisco Router - DHCP

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Chapter 4 Managed Devices

1. Linux Server

a. Packages installation

# yum install net-snmp-libs net-snmp net-snmp-utils b . File Configuration

# vi /etc/snmp/snmpd.conf

# sec.name source community

com2sec local localhost jeong

com2sec mynetwork 192.168.80.0/24 jeong

# groupName securityModel securityName

group MyROGroup v1 mynetwork group MyROGroup v2c mynetwork

# Make at least snmpwalk -v 1 localhost -c public system fast again. # name incl/excl subtree mask(optional)

#view systemview included .1.3.6.1.2.1.25.1.1

view all included .1 80

# Finally, grant the group read-only access to the systemview view. # group context sec.model sec.level prefix read write notif

access MyROGroup "" any noauth exact all none none access MyRWGroup "" any noauth exact all all none # Check the / partition and make sure it contains at least 10 megs.

disk / 10000

c. Service checking

# service snmpd start # chkconfig snmpd on

# ps –ef | grep snmpd ; netstat –nau | grep 161

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Chapter 4 Managed Devices

2. Windows Server 2008



Install snmp files

 Start -> Administrative Tools -> Services -> SNMP Service – > Properties -> Security

① _{Add Community : jeong}

② _{Add Hosts : 192.168.80.6 (NMS IP)}

3. Cisco Router and Switch

router# config terminal

router(config)# snmp-server contact [email protected]

router(config)# access-list 5 permit 192.168.80.6

router(config)# snmp-server community jeong RO 5 router(config)# snmp-server host 192.168.80.6 jeong

router(config)# int lo 0

router(config)# ip address 1.1.1.1 255.255.255.0 router(config)# exit

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Chapter 5 MRTG Configuration

1.MRTG Installation

# yum install httpd php zlib libpng gd mrtg 2. Creating configuration files for each device

# cfgmaker --global 'WorkDir: /var/www/mrtg' --output /etc/mrtg/mrtg.cfg

[email protected] // Linux Server

# cfgmaker --global 'WorkDir: /var/www/mrtg' --output /etc/mrtg/windows.cfg

[email protected] // Windows Server

#cfgmaker --global 'WorkDir: /var/www/mrtg' --output /etc/mrtg/router.cfg

[email protected] // Router

# vi mrtg.sh //shell script to execute MRTG using cfg files

#!/bin/bash

LOCK=/var/lock/mrtg/mrtg_l

CONFCACHE=/var/lib/mrtg/mrtg.ok

env LANG=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg --lock-file $LOCK --confcache-file $CONFCACHE env LANG=C /usr/bin/mrtg /etc/mrtg/windows.cfg --lock-file $LOCK --confcache-file $CONFCACHE env LANG=C /usr/bin/mrtg /etc/mrtg/router.cfg --lock-file $LOCK --confcache-file $CONFCACHE

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Chapter 5 MRTG Configuration

3. Editing cfg files for each Devices

a. Editing 3 files for managed devices

# vi mrtg.cfg windows.cfg router.cfg



Target[eth0]: \eth0:[email protected]:



SetEnv[eth0]: MRTG_INT_IP="192.168.80.5" MRTG_INT_DESCR="eth0"



MaxBytes[eth0]: 1250000



Title[eth0]: eth0 -- server.chul.com



PageTop[eth0]: <h1>eth0 -- server.chul.com</h1>

b. Executing shell script

# ./mrtg.sh

# ls –l /var/www/mrtg

c. Creating index file

# indexmaker –output=/var/www/mrtg/index.html mrtg.cfg windows.cfg router.cfg

d. Webserver reload

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Chapter 5 MRTG Configuration

4. Access Control for MRTG Access

# vi /etc/httpd/conf.d/mrtg.conf Alias /mrtg /var/www/mrtg

<Location /mrtg> Order deny,allow Deny from all

Allow from 127.0.0.1 192.168.80.0/24 </Location>

[root@centos ~]# service httpd reload

5. Crontab

#vi /etc/cron.d/mrtg

/5 * * * root /root/mrtg.sh

# service crond start

# chkconfig crond on

6. Testing MRTG Graph

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Chapter 6 Adding More Targets

1. CPU

## CPU Load Average ###

Target[cpu]: .1.3.6.1.4.1.2021.10.1.5.1&.1.3.6.1.4.1.2021.10.1.5.2:[email protected] MaxBytes[cpu]: 100

Unscaled[cpu]: dwmy

Options[cpu]: gauge, absolute, growright, noinfo, nopercent YLegend[cpu]: CPU Load(%)

ShortLegend[cpu]: (%)

LegendI[cpu]: 1 minute average LegendO[cpu]: 5 minute average Legend1[cpu]: 1 minute average(%) Legend2[cpu]: 5 minute average(%) Title[cpu]: ＣＰU usage

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Chapter 7 Email Notification

1. mrtg.cfg in /etc/mrtg

a. Global section

WorkDir: /var/www/mrtg

ThreshDir: /var/run/mrtg

b. Per each Target

Target[cpu]:

Options[cpu]: growright, nopercent, gauge

ThreshMaxI[cpu]: 90

ThreshMinI[cpu]: 50

ThreshProgI[cpu]: /usr/local/sbin/notify.sh

2. Need to check SMTP working for email notification

3. /usr/local/sbin/notify.sh

#!/bin/sh

echo -e "Device: $1\\nThreshold Value : $2\\nCurrent Value: $3\\nDate/Time :

`date`\\n" | mail -s "Threshold Alert: '$1' Passed $2 Threshold"

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Chapter 8 MRTG Authentication

1.Web server configuration

# vi /etc/httpd/conf/httpd.conf

AllowOverride FileInfo AuthConfig Limit Options MultiViews Indexes IncludesNoExec </Directory

Knowledge is Power. He who gets wisdom loves his own soul; he who cherishes understanding prospers. (Proverbs 19:8)