To monitor your ESX 3.5 server by using SNMP, we need to enable SNMP on ESX before adding it to your monitoring software. This How-To will show you the steps involved.
Log Into ESX Server

Log into your ESX Server either through SSH or through the console of the server.
Use Nano to Edit Snmpd.conf

Use Nano (which is a notepad like text editor) to edit the file /etc/snmp/snmpd.conf file by using the command:
nano /etc/snmp/snmpd.conf
Add SNMP Community to Config File

Use the arrow keys to go down to the section “rocommunity public”. Replace “public” with your community string for your environment (1). Then use “Ctrl+X” to exit out of Nano. You’ll be asked if you would like to save. Type in “y” for yes and hit enter. Press enter again when confirming the filename to save as.
Enable SNMP to Start Automatically After a Reboot

Since SNMP is not started by default, you’ll need to type in this command to ensure it will be started after a reboot of the ESX server. The command is:
chkconfig snmpd on
Enable SNMP Through the ESX Firewall

We’ll need to allow SNMP traffic through the built-in ESX firewall. To do this, type in the following command:
esxcfg-firewall -e snmpd
Start the SNMP Service

Now we’re ready to start the SNMP service. Type in:
service snmpd start
Ready for Monitoring
At this point, SNMP is enabled on your ESX 3.5 server and you can monitor it using your SNMP monitoring software! Happy monitoring!
February 23, 2009 at 11:07 pm
If you need information regarding the ESX MIBs, you can find it in the VI3 Admin Guide:
http://vmware.com/pdf/vi3_35/esx_3/r35/vi3_35_25_admin_guide.pdf
If you simply need to enable SNMP traps to your monitoring solution (used in conjunction with Virtual Center alert notification), you can find this in the VI Client under the menu: Administration > VirtualCenter Management Server Configuration
May 15, 2009 at 8:19 am
Thank you – That procedure worked and saved my back-side!
April 7, 2010 at 2:10 pm
[...] blog post on how to configure SNMP on a ESX 3.5 server which I plan on using à http://blog.lewan.com/2009/02/23/how-to-setup-snmp-on-esx-35-servers/ In the end your logs are only as useful to you if someone looks at [...]