CACTI - The Easy Tutorial - Configure your SNMP clients

Cacti SNMP clients
Last Change : Jan 27 2008

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Details What is Cacti?
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SNMP clients

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HOW to activate the SNMP clients

SNMP agents must be only run in Read-Only (RO) mode because the SNMP poller needs only to read data on the remote machines. Limiting how has the right to poll the agents on the remote devices increase a little the security.
Never forget that the SNMP community string is going across the network in the clear and can be intercepted easily with tools like WireShark, the former Ethereal.

1. LINUX 2. WINDOWS 3. CISCO 4. NETSCREEN

1. On a debian/Ubuntu Linux machine:

Install the SNMP daemon:

#apt-get install snmpd
Configure the SNMP daemon:
Edit /etc/snmp/snmpd.conf
Comment the "com2sec paranoid default public" line and uncomment the "com2sec readonly default public" line. Don't forget to configure your SNMP community and limit who has the right to poll the SNMP daemon:

#com2sec paranoid default public
com2sec readonly snmp_server_ip_address your_snmp_community
#com2sec readwrite default private
For example:
com2sec readonly 10.0.0.1 armageddon
Where 10.0.0.1 is the SNMP poller server and armageddon the SNMP read-only community.

Always in the /etc/snmp/snmpd.conf file, you can configure the SNMP syslocation and syscontact settings.
Look for the lines beginning with syslocation and syscontact and do your changes:

syslocation Geneva/Switzerland
syscontact Roger Rabbit
Then restart the SNMP daemon:

/etc/init.d/snmpd restart

2. On a Windows machine:

Install the SNMP daemon:

Click on: Start -> Control Panel -> Add/Remove Programs -> Add/Remove Windows Components -> Management and Monitoring Tools -> Simple Network Management Protocol -> Ok -> next
This will install the SNMP agent on the Windows machine.

Configure the SNMP daemon:

Clic on Start -> run -> enter "services.msc"
Scroll down and click on the SNMP service.
Configure the security tab as below.

SNMP Service Properties (Local Computer) Security Tab

Where armageddon is the SNMP read-only community and 10.0.0.1 the SNMP poller.

optionnaly, you can configure the Contact and Location SNMP settings.

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3. On a Cisco machine running an IOS software:

Cisco_device#conf t
Cisco_device(config)#snmp-server community "your_community" RO
A little more secure configuration:

Cisco_device#conf t
Cisco_device(config)#snmp-server community "your_community" RO 1
Cisco_device(config)#access-list 1 permit "snmp_server_IP_address"
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4. On a Netscreen-25 firewall:

you can configure the SNMP settings either through the command line interface or through a web interface.

The CLI:

set snmp community "armageddon" Read-Only Trap-on traffic version any
set snmp host "armageddon" 192.168.1.22 255.255.255.255 trap v2
set snmp location "Greenland"
set snmp contact "Erik the Red"
set snmp name "ns25"
set snmp port listen 161
set snmp port trap 162
Here the 192.168.1.22 host has the right to poll the netscreen firewall with read-only rights.

The Web Interface:

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