SNMP

SNMP is a network management protocol that allows for the monitoring and management of network devices.

The SNMP adapter enables Axonius to discover and inventory physical components of network infrastructure devices using the industry-standard SNMP protocol.

Use Cases the Adapter Solves

• Network Device Discovery: Discover and inventory network infrastructure devices (routers, switches, firewalls) across your network using SNMP.
• Neighbor Device Visibility: Identify devices connected to your network infrastructure through ARP table analysis to detect unmanaged endpoints.
• Network Topology Mapping: Build comprehensive network topology maps by correlating device interfaces, IP addresses, and MAC addresses from SNMP data.

Asset Types Fetched

• Devices (Network Devices)

Data Retrieved through the Adapter

Devices

• Host Name, Device Name, Serial Number
• Object ID, Contact, Location
• Device Type, Discovery Protocol, Uptime
• Network Interfaces (MAC addresses, IP addresses, interface status)
• LLDP Neighbors (when Fetch LLDP neighbors is enabled): Local Port Number, Local Port ID, Local Port Description, Remote Index, Chassis ID Subtype, Chassis ID, Port ID Subtype, Port ID, Port Description, System Name, System Description, Management Addresses. The neighbors are also added to the Connected Devices and Direct Connected Devices fields.

Before You Begin

Required Ports

• UDP port 161 (SNMP)

Authentication Methods

The SNMP adapter supports three authentication methods:

SNMPv1/v2c Authentication

Uses community string-based authentication. The adapter authenticates using a read community string configured on the target device.

SNMPv3 Authentication

Uses username-based authentication with optional authentication and privacy (encryption) protocols. Supports multiple authentication algorithms (MD5, SHA, SHA224, SHA256, SHA384, SHA512) and privacy algorithms (DES, DES3, AES128, AES192, AES256).

APIs

Axonius uses the SNMP protocol to query network devices. The following MIB objects are queried:

• GET SNMPv2-MIB::sysDescr - System description
• GET SNMPv2-MIB::sysName - System name
• GET SNMPv2-MIB::sysContact - System contact information
• GET SNMPv2-MIB::sysLocation - System physical location
• GET SNMPv2-MIB::sysObjectID - Vendor identification
• GET SNMPv2-MIB::sysUpTime - System uptime
• GETBULK IF-MIB::ifTable - Network interface information
• GETBULK IP-MIB::ipNetToPhysicalTable - ARP table for neighbor discovery
• GETBULK IP-MIB::ipNetToMediaTable - Legacy ARP table (for older devices)

Required Permissions

The SNMP adapter requires read-only access to the device's SNMP agent. In addition, each SNMP version has different requirements:

For SNMPv1/v2c:

• Configure a read community string on the target device.
• Ensure the community has read access to system and interface MIBs.

For SNMPv3:

• Create a user account on the target device's SNMP agent.
• Grant read access to system and interface MIBs.
• Configure appropriate authentication and privacy settings.

Supported from Version

Supported from Axonius version 6.1.0

Setting Up SNMP to Work with Axonius

The SNMP protocol must be enabled on your network devices before connecting to Axonius. Configuration steps vary by device vendor:

1. Enable SNMP agent on the target network device.
2. Configure authentication credentials:
   • For SNMPv1/v2c: Set a read community string (for example, public or a custom string).
   • For SNMPv3: Create a user with authentication and privacy settings.
3. Allow SNMP access from the Axonius instance's IP address (configure ACLs if needed),
4. Verify the connectivity by testing SNMP queries from the Axonius instance to the target device on UDP port 161.

Connecting the Adapter in Axonius

1. Navigate to the Adapters page, search for SNMP, and click on the adapter tile.
2. Click Add Connection.

To connect the adapter in Axonius, provide the following parameters:

Required Parameters

1. Host Name, CIDR, or IP range - The hostname, IP address, CIDR (e.g. 192.168.1.0/24), or IP range (e.g. 192.168.1.1-192.168.1.50) of the SNMP device(s) the adapter queries. When entering an IP range, you can discover and fetch data from multiple SNMP devices in a single adapter connection instead of creating separate connections for each device.
   • The adapter creates a separate device for each host in the range that responds, and includes the host's IP address in the device data.
   • When you save the connection, the adapter checks up to 256 hosts in the range. The check succeeds when at least one of these hosts responds.
   • If no host in the range responds during a fetch, the fetch fails and the error message lists the hosts that failed.
2. Version - The SNMP protocol version to use. Options: 1 (SNMPv1), 2c (SNMPv2c; default), or 3 (SNMPv3). The credentials you need depend on the version you select:

Optional Parameters

1. Port - The UDP port for SNMP communication. Default: 161

To learn more about common adapter connection parameters and buttons, see Adding a New Adapter Connection.

Advanced Settings

1. Fetch LLDP neighbors (default: disabled) - Select to read the LLDP neighbors (LLDP-MIB) of each device. Enabling this option adds SNMP requests per device. Make sure that LLDP is enabled on the network devices and that the SNMP credentials can read the LLDP-MIB.

Related Enforcement Actions

• SNMP - Enrich Asset Data

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