Configure SNMP for SolarWinds Platform agents on Linux/Unix and AIX systems in SAM

SolarWinds Platform agents provide a secure, encrypted communication channel between the SolarWinds Platform server and Windows, Linux/Unix, or AIX systems, as an alternative to WMI or SNMP to gather data about key servers, processes, and applications in your environment.

This topic describes how to set up SNMP on Linux/Unix and AIX systems that use SolarWinds Platform agents for:

In addition to an overview about Discovery, this topic describes tasks you may need to perform, depending on the environment, including:

Install SNMP daemons on Linux/Unix systems
Configure SNMPv3 on Linux/Unix systems
Enable SNMP daemons on AIX systems

How Discovery works for Linux/Unix and AIX systems

Depending on settings, Discovery can automatically configure SNMP on systems when it detects new or updated nodes. If a node is configured to support SolarWinds Platform agents, the Discovery wizard completes the following tasks:

Checks for an SNMP daemon on the target system that binds to default port 161 and awaits requests from the SolarWinds Platform
Verifies that SNMP credentials for the system match credentials for the related node, as configured in the SolarWinds Platform.
Deploys an SolarWinds Platform agent to the node.
Configures the snmpd agent to start automatically after the system reboots.
Scans the snmpd.conf file on the target system for an agent-owned community string on SNMPv1 or SNMPv2c nodes. If no string exists, a randomly generated community string is added and the SNMP service restarts.
```
### BEGIN SolarWinds Agent SNMP auto config
rocommunity Community_String localhost
### END SolarWinds Agent SNMP auto config
```
SNMPv3 communication is encrypted by default; no community strings are involved.

Note that if an snmpd.conf file changes (for example, to adjust access policies), the SolarWinds Platform will block future updates to the file. That functionality protects any changes to the file, but it also impacts how the SolarWinds Platform interacts with a target system in the future.

For example, suppose a Linux system is initially configured for agentless SNMP polling, but then you decide to collect Asset Inventory or Hardware Health from the node with an SolarWinds Platform agent. SNMP polling continues but the SolarWinds Platform agent will not function.

To resolve that issue, manually edit the snmpd.conf file to add a read-only community string.

rocommunity Your_Community_String localhost

To learn more about configuration files for snmpd agents, see:

SNMPD.CONF and tutorial (available at www.net-snmp.org)
snmpd.examples (available at linux.die.net).

Install SNMP daemons on Linux/Unix systems

As mentioned earlier, the SolarWinds Platform can configure SNMP automatically during Discovery for Linux/Unix systems that host an enabled SNMP daemon called snmpd.

To install the snmpd daemon, use one of these commands, depending on your distribution type.

For Ubuntu: sudo apt-get -y install snmpd
For Red Hat/CentOS: yum -y install net-snmp
For SUSE: zypper -y install net-snmp

After installing the SNMP daemon, trigger auto-configuration by either:

Clicking List Resources in the Management widget on the Node Details view.
Running Discovery again. For tips, watch Create a Manual Discovery Job.

If automated configuration still fails, try setting up the daemon manually. The following steps assume the target system is already configured to support SolarWinds Platform agents.

Install the SNMP daemon on the target system. Steps vary by Linux/Unix distribution type.
For SNMPv1 or SNMPv2c, add a read-only community string to the snmpd.conf file.
```
rocommunity Your_Community_String localhost
```
SNMPv3 does not use community strings; it has built-in encryption.
In the SolarWinds Platform Web Console, navigate to the Node Details page and click Edit Node. Under Polling Method, the "Windows and Unix/Linux Servers: Agent" option should be selected.
Switch to the UNIX/LINUX tab and select Include SNMP Credentials.
For SNMPv1 or SNMPv2c, add the Community String from step 2, as shown here.

For SNMPv3, add credentials and specify authentication and encryption options.
Click Submit.
On the target system, restart the SNMP daemon.

To enable snpmd logging, start the daemon with parameters for maximum file size and debug level that vary based on snmpd version and Linux distribution. See your Linux/Unix documentation for details.

Configure SNMPv3 on Linux/Unix systems

SNMPv3 is a secure version of the SNMP protocol that includes authentication and encryption. When you add multiple nodes with Discovery or add a single node, you can specify SNMPv3 as the version and provide required details, such as credentials.

If the SolarWinds Platform detects that SNMPv3 is already configured for a node, it won't modify the existing SolarWinds Platform configuration automatically. You'll need to edit it manually, as described next.

Navigate to the Node Details page and click Edit Node. Under Polling Method, the "Windows and Unix/Linux Servers: Agent" option should already be selected.
Switch to the UNIX/LINUX tab and select the Include SNMP Credentials option.
Select SNMPv3 as the SNMP Version.
When SNMPv3-specific fields appear, provide credentials, an authentication method, a privacy/encryption method, and the Credential Set Library to use, as necessary.
Click Submit.

Enable SNMP daemons on AIX systems

By default, AIX systems include an SNMP daemon, but it is not enabled. To support communication with the SolarWinds Platform, enable the SNMP daemon, as described in Poll SNMP on AIX computers.

The proprietary IBM daemon does not support some key MIBs that expose details such as processes and resource consumption. Consider using NET-SNMP for AIX, available at www.net-snmp.org, as described in How to configure SNMP on Linux and Unix.

Learn more

As with other features shared by multiple SolarWinds Platform modules, you can learn more about SolarWinds Platform agents in the SolarWinds Platform Administrator Guide, including: