An It-Slave in the digital saltmine

This guide describe howto install and do a basic configure of SNMP on a RedHat Enterprise Linux or CentOS. Probably it will work on many other *nix systems.

1. Installation

Run command yum install net-snmp-utils

[root@dull etc]# yum install net-snmp-utils
Loading "fastestmirror" plugin
Loading "dellsysidplugin" plugin
...
...
Dependencies Resolved

=============================================================================
 Package                 Arch       Version          Repository        Size
=============================================================================
Installing:
 net-snmp-utils          i386       1:5.3.1-24.el5_2.2  updates           182 k
Installing for dependencies:
 net-snmp                i386       1:5.3.1-24.el5_2.2  updates           698 k

Transaction Summary
=============================================================================
Install      2 Package(s)
Update       0 Package(s)
Remove       0 Package(s)

Total download size: 879 k
Is this ok [y/N]: y

Answer y

Downloading Packages:

(1/2): net-snmp-utils-5.3 100% |=========================| 182 kB    00:02
(2/2): net-snmp-5.3.1-24. 100% |=========================| 698 kB    00:06
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
 Installing: net-snmp                     ######################### [1/2]
  Installing: net-snmp-utils               ######################### [2/2]
Installed: net-snmp-utils.i386 1:5.3.1-24.el5_2.2
Dependency Installed: net-snmp.i386 1:5.3.1-24.el5_2.2
Complete!

Now it is installed

2. Configure

I’m careful so I do a backup of the snmpd config file.

[root@dull ~]# mv /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.org 

Create a new config file.

[root@dull ~]# vi /etc/snmp/snmpd.conf

rocommunity  public
syslocation  "PDC, Peters DataCenter"
syscontact  peter@it-slav.net

Start the snmpd service

[root@dull ~]# /etc/init.d/snmpd start

Do a snmpwalk to make sure it is working

[root@dull ~]# snmpwalk -v 1 -c public -O e 127.0.0.1
SNMPv2-MIB::sysDescr.0 = STRING: Linux dull 2.6.18-92.1.17.el5 #1 SMP Tue Nov 4 13:45:01 EST 2008 i686
SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (16748) 0:02:47.48
SNMPv2-MIB::sysContact.0 = STRING: peter@it-slav.net
SNMPv2-MIB::sysName.0 = STRING: dull
SNMPv2-MIB::sysLocation.0 = STRING: "PDC, Peters DataCentral"
SNMPv2-MIB::sysORLastChange.0 = Timeticks: (1) 0:00:00.01
...

...

Yes, it is working

And finally, make sure snmpd starts next time you restart your machine.

[root@dull ~]# chkconfig snmpd on

3. Monitor example

Below is an example of how it looks using op5 Monitor a Nagios based Enterprise Monitor solution.

4. Useful links

• op5 Statistics, a cacti based graph tool
• op5 Monitor, an Enterprise Class Monitoring system based on Nagios
• Net-SNMP, an open source implementation of SNMP
• Cacti, an open source graph tool
• Nagios, the number 1 monitor tool

4 Responses to “Install and configure SNMP on RHEL or CentOS”

1. Paul Says:
   July 27th, 2009 at 19:49

   Is there any way to get around the dependency on lm_sensors? I am not comfortable installing this highly insecure package on my servers.

2. Andrew Says:
   September 9th, 2009 at 18:08

   @Paul: This notice may help: http://www.pro-linux.de/security/4126 This vulnerability was fixed in ver. 2.9.1-r1.

3. Anders Says:
   February 24th, 2010 at 13:29

   Hi,
   thanks for the guide, helpded me!
   But, I wonder if you have a guide for snmptraps för redhat aswell?

4. peter Says:
   February 24th, 2010 at 14:14

   Hi Anders,

   No I do not. Avoid traps is my answer. Traps looks like a good idea but in the long term it takes away the responsibility from the owner of the problem to the poor person that handles the monitor system.

   Read my general monitoring guideline:-)
   http://www.it-slav.net/blogs/2009/08/30/general-systems-and-network-management-guidelines-part-1/

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