Configuration: SNMP based monitoring of VM

Configuration: SNMP-based monitoring of  RHEL VM

 Here are the detailed steps to monitor a RHEL (Red Hat Enterprise Linux) VM via SNMP using Zabbix:

1. Install SNMP and SNMP Utilities on RHEL VM: First, you need to install the SNMP and SNMP utilities on your RHEL VM

sudo yum install net-snmp net-snmp-utils

net: Short for network, indicating the tools are network-related.

snmp: Simple Network Management Protocol, the protocol used for network management.

utils: Short for utilities, meaning the package contains various tools and programs for SNMP.

2. Configure SNMP on RHEL VM: Edit the SNMP configuration file:

sudo vi /etc/snmp/snmpd.conf

Add or modify the following lines to configure SNMP:

# Map the community name "public" into a "security name"

com2sec notConfigUser  default       public

# Map the security name into a group name

group   notConfigGroup v1            notConfigUser

group   notConfigGroup v2c           notConfigUser

# Create a view for us to let the group have rights to:

view    systemview    included   .1.3.6.1.2.1.1

view    systemview    included   .1.3.6.1.2.1.25.1.1

# Finally, grant the group read-only access to the systemview view.

access  notConfigGroup ""      any       noauth    exact  systemview none none

3. Start and Enable the SNMP Service: Start the SNMP service and ensure it starts on boot.

sudo systemctl start snmpd

sudo systemctl enable snmpd

4. Configure Firewall to Allow SNMP Traffic: If you have a firewall enabled, allow SNMP traffic.

sudo firewall-cmd --permanent --add-service=snmp

sudo firewall-cmd --reload

5. Verify SNMP Configuration: You can test the SNMP configuration using the snmpwalk command:

snmpwalk -v 2c -c public localhost

This should return a list of SNMP OIDs and their values if everything is configured correctly.

Note: SNMP Community String: An SNMP community string acts like a password that grants access to a device's SNMP data. There are typically two types of community strings.

1. Read-Only (RO): Allows only retrieval of information.
2. Read-Write (RW): Allows retrieval and modification of information.

Commonly, the default community string is "public" for read-only access. 

• Community strings authenticate the requests sent to the SNMP device. They ensure that only authorized users can access the device's SNMP data.
• They define what level of access is granted—whether the requester can only read data or also modify settings.