How do I configure SNMP on Linux or Unix?

SNMP v1/v2c

On Linux or Unix, you will need configure snmpd.conf. The operating system itself may or may not have snmpd installed by default. If you don’t see the /etc/snmp/snmpd.conf file, you will need to install net-snmp first.

For Debian:

sudo apt update
sudo apt install snmpd

For Redhat:

yum install net-snmp

Once you are sure it is installed, you can proceed to use the basic configuration sample below. Refer to the documentation here for all the potential configuration options: SNMP_CONFIG and here: SNMPD.CONF.

Once you update your /etc/snmp/snmpd.conf file properly, restart snmpd. Note that you will want to replace “wugninja” with your own community string and “192.168.1.0/24” with your own allowed network(s), use this configuration for SNMP v1 and v2:

syslocation Office123
syscontact [email protected]
rocommunity wugninja

## sec.name source community
## ======== ====== =========
com2sec local localhost wugninja
com2sec network_1 192.168.1.0/24 wugninja

## Access.group.name sec.model sec.name
## ================= ========= ========
group MyROGroup_1 v1 local
group MyROGroup_1 v2c network_1

## MIB.view.name incl/excl MIB.subtree mask
## ============== ========= =========== ====
view all-mibs included .1 80

## MIB
## group.name context sec.model sec.level prefix read write notif
## ========== ======= ========= ========= ====== ==== ===== =====
access MyROGroup_1 "" v1 noauth exact all-mibs none none
access MyROGroup_1 "" v2c noauth exact all-mibs none none

##This setting disables the log messages for accepted connections
##Denied connections will still be logged
dontLogTCPWrappersConnects yes

##This setting forces network disks to show as 'fixed disks'
##as required by WUG disk utilization monitor
storageUseNFS 2

SNMP v3

But what if you want to use SNMP v3 instead? The configuration is a bit simpler. Not only that, but SNMP v3 also uses authentication and encryption so it is much more secure when compared to v1/v2. The first step is creating the SNMP v3 user account:

• Stop snmpd (different commands depending on your *nix flavor)
  • service snmpd stop
  • systemctl stop snmpd
• Run the command
  • net-snmp-create-v3-user
• Follow the steps from the command to create a user
• Once done, start your snmpd service
  • service snmpd start
  • systemctl start snmpd

Then your final snmpd.conf should look something like this, replacing ‘snmpadmin’ with your created username:

rwuser snmpadmin
syslocation Office123
syscontact [email protected]
##This setting disables the log messages for accepted connections
##Denied connections will still be logged
dontLogTCPWrappersConnects yes
##This setting forces network disks to show as 'fixed disks'
##as required by WUG disk utilization monitor
storageUseNFS 2