CentOS / RHEL 7 : Install and Configure SNMPv3

Please find below Steps to configure SNMPv3.

1. Install the required packages

# yum install net-snmp net-snmp-utils net-snmp-devel -y

2. Create User

Turn off the agent  the snmpd agent.

# systemctl stop snmpd

There are Three ways you can create the user.

1. CLI Mode

2. Interactive Mode

3. Manually

1. CLI mode

The syntax of "net-snmp-config –create-snmp3-user" is as below :

net-snmp-config --create-snmpv3-user [-ro] [-A authpass] [-X privpass] [-a MD5|SHA] [-x DES|AES] [username]

Default authentication method is MD5 and default encryption is DES if not explicitly specified.

# net-snmp-config --create-snmpv3-user -a MD5 -A testsnmp123 testsnmp

2. Interactive Mode

You can also use interactive mode to enter username and password as follows :

# net-snmp-create-v3-user

Enter a SNMPv3 user name to create:

testsnmp

Enter authentication pass-phrase:

testsnmp123

Enter encryption pass-phrase:

[press return to reuse the authentication pass-phrase]

adding the following line to /var/lib/net-snmp/snmpd.conf:

createUser testsnmp MD5 "testsnmp123" DES

adding the following line to /etc/snmp/snmpd.conf:

rwuser testsnmp

3. Manual

To manually add the user – add below line to the file /var/lib/net-snmp/snmpd.conf :

createUser testsnmp MD5 "testsnmp123" DES

and add below lines to the file /etc/snmp/snmpd.conf

rwuser testsnmp

The sample username is testsnmp and pass-phrase is testsnmp123.

3. Start the service

Configure the SNMP services to start on each reboot :

# systemctl enable snmpd

Start the snmpd service :

# systemctl start snmpd

4. Test the setup using snmpwalk command

# snmpwalk -v3 -u testsnmp -l authNoPriv -a MD5 -A testsnmp123 localhost

Here,

-v3 - specifies version

-u - specifies username

-l - specifies security level

-a - specifies Authentication Protocol

-A - specifies Pass-phrase