Configuring SNMP Agents on different Linux Servers

Monitor your Linux servers agentless, with the support of SNMP. Simply install and configure SNMP agents on your servers, install an On-Premise Poller, and your server for monitoring. 

Linux flavours

• Ubuntu
• CentOS
• Oracle Solaris
• FreeBSD
• Red Hat Enterprise Linux (RHEL)
• Debian
• Fedora
• macOS

Ubuntu

Installation

Execute the command:

> apt update
> apt install snmpd

Configuration

Edit the file: /etc/snmp/snmpd.conf 

1. 1. Set the SNMP v1 Read-Only Community String as 'public' by adding the line: 
      rocommunity public
   2. #agentAddress udp is the IP address from which SNMP requests will be accepted by the server. Hence, comment the line:
      #agentAddress udp:127.0.0.1:161
   3. For the same reason mentioned above, uncomment the line: 
      agentAddress udp:161,udp6:[::1]:161
   4. Restart the SNMP Service:
      service snmpd restart

Allowing SNMP ports in firewall

Execute the following commands to allow necessary ports:

ufw allow 161/udp
ufw allow 162/udp

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CentOS

Installation

Execute the commands:

> yum update
> yum install net-snmp

Configuration

Edit the file: /etc/snmp/snmpd.conf 

1. 1. Set the SNMP v1 Read-Only Community String as 'public' by adding the line: 
      rocommunity public
   2. Replace the line below:
      view systemview included .1.3.6.1.2.1.25.1.1
      with the following line:
      view systemview included .1.3.
   3. Restart the SNMP Service:
      service snmpd restart

Allowing SNMP ports in Firewall

Execute the commands:

firewall-cmd --zone=public --add-port=161/udp --permanent
firewall-cmd --zone=public --add-port=162/udp --permanent
firewall-cmd --reload

---

Oracle Solaris

Execute the command:

svcadm enable net-snmp

---

FreeBSD

1. Fetching Ports Collection

The FreeBSD operating system offers Ports Collection as a simple way to install SNMP applications.

Execute the commands:

portsnap fetch
portsnap extract

2. Installing net-snmp

cd /usr/ports/net-mgmt/net-snmp
make install clean

Click OK on the next screen and wait for the installation to complete.

3. Configuration file

1. 1. Copy the following configuration file:
      cp /usr/local/share/snmp/snmpd.conf.example /usr/local/etc/snmpd.conf
   2. Set the SNMP v1 Read-Only Community String as 'public' by adding the line: 
      rocommunity public
   3. #agentAddress udp is the IP address from which SNMP requests will be accepted by the server. Hence, comment the line:
      #agentAddress udp:127.0.0.1:161
   4. For the same reason mentioned above, uncomment the line:
      agentAddress udp:161,udp6:[::1]:161

4. Firewall configuration

Edit the /etc/rc.conf file and add the following lines:

snmpd_enable="YES"
snmpd_conffile="/usr/local/etc/snmpd.conf"

5. Starting the SNMP Service

service snmpd start

---

RHEL

Installation

1. 1. Execute the command:
      yum install -y net-snmp
   2. Set the SNMP v1 Read-Only Community String as 'public' by adding the line below to the configuration file (/etc/snmp/snmpd.conf):
      rocommunity public
   3. #agentAddress udp is the IP address from which SNMP requests will be accepted by the server. Hence, comment the line:
      agentAddress udp:161,udp6:[::1]:161
   4. Start the snmpd service:
      systemctl enable snmpd && systemctl start snmpd

Allowing SNMP ports in firewall

Execute the following commands:

firewall-cmd --zone=public --add-port=161/udp --permanent
firewall-cmd --zone=public --add-port=162/udp --permanent
firewall-cmd --reload

---

Debian

Installation

Execute the commands:

> apt update
> apt install snmpd

Configuration

Edit the file: /etc/snmp/snmpd.conf 

1. 1. Set the SNMP v1 Read-Only Community String as 'public' by adding the line: 
      rocommunity public
   2. #agentAddress udp is the IP address from which SNMP requests will be accepted by the server. Hence, comment the line:
      #agentAddress udp:127.0.0.1:161
   3. For the same reason mentioned above, uncomment the line: 
      agentAddress udp:161,udp6:[::1]:161
   4. Restart the snmpd service:
      /etc/init.d/snmpd restart

---

Fedora

Installation

1. 1. Execute the following command:
      > yum install net-snmp
   2. Set the SNMP v1 Read-Only Community String as 'public' by adding the line below to the configuration file (/etc/snmp/snmpd.conf):
      rocommunity public
   3. Restart the snmpd service:
      /bin/systemctl restart snmpd.service

Firewall Configuration

Excecute the following commands to allow the necessary ports:

firewall-cmd --zone=public --add-port=161/udp --permanent
firewall-cmd --zone=public --add-port=162/udp --permanent
firewall-cmd --reload

---

macOS

Configuration

1. 1. Edit the SNMP configuration file (/etc/snmp/snmpd.conf) and set the SNMP v1 Read-Only Community String as 'public' by adding the line:
      rocommunity public
   2. Start the snmp service:
      sudo launchctl load -w /System/Library/LaunchDaemons/org.net-snmp.snmpd.plist

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Testing SNMP on Linux 

Test the SNMP reachability using MIB browser

Related articles

• Configuring SNMP agents on different Windows servers
• Adding a server monitor (agentless)