Network Device Scanning

A network device scanner uses Simple Network Management Protocol (SNMP) to scan a network for connected devices and help ensure they’re running properly. This capability allows you to conduct discovery and mapping and can help support fault, performance, and availability monitoring. Overall, network device scanning gives you a comprehensive view of your network devices, which can help you more easily ensure the health, security, and performance of your network.

With its Network Insight™ features, NPM helps you ensure comprehensive monitoring for advanced network devices like F5 BIG-IP load balancers, Cisco ASA and Palo Alto Networks firewalls, and Cisco Nexus switches.

NPM is a network device finder designed to simplify staying on top of devices with the integrated Orion^® Platform Discovery Wizard too, which can automatically scan networks for devices and add them to your monitoring database. It uses the network panel to scan devices by IP addresses, subnets, or IP range. You can also scan via Active Directory, which is ideal for a team setting, as you won't need to manually aggregate every IP address on certain sections of the network and can instead scan entire subnets in a matter of seconds.

Before you begin, you'll want to make sure you've enabled the networking devices you want to monitor for SNMP and Windows devices for WMI.

After you have configured SolarWinds NPM, log in to NPM and scan the network for devices to monitor.

Before discovering your network, take these steps:

1. If the Discovery Wizard does not start automatically after configuration, click Settings > Network Discovery.
2. Click Add New Discovery, and then click Start.
3. If this is your first discovery, add a limited number of IP addresses on the Network panel.
4. If the Agents panel appears, you’ve enabled the Quality of Experience (QoE) agent during installation. The QoE agent monitors packet-level traffic. If any nodes are using agents, select the Check all existing nodes check box.
   
   This setting ensures any agents you deploy, including the one on your Orion server, are up to date. If there are no nodes using agents, you can leave this option unchecked.
5. On the Virtualization panel, to discover VMware vCenter or ESX hosts on your network:
1. Check Poll for VMware and click Add vCenter or ESX Credential.
2. Select <new credential> and provide required information.
6. On the SNMP panel:
1. If all devices on your network require only the default SNMPv1 and SNMPv2 public and private community strings, click Next.
2. If any device on your network uses a community string other than public or private, or if you want to use an SNMPv3 credential, click Add Credential and provide the required information.
7. On the Windows panel, to discover WMI or RPC-enabled Windows devices, click Add New Credential and provide the required information.
8. On the Monitoring Settings panel, SolarWinds recommends manually setting up monitoring the first time you run discovery. This allows you to review the list of discovered objects and select the ones you want to monitor.
   
   When you scale monitoring, you can configure discovery to automatically start monitoring objects it finds.
9. On the Discovery Settings panel, click Next.
10. Accept the default frequency and run the discovery immediately.

Scanning for network devices can take anywhere from a few minutes to a few hours, depending on the number of network elements the system discovers.

The following options are available to discover devices on the network and when to use these different options:

• IP Ranges: Use this option when you want the Orion Platform to scan one or more IP ranges. If you have many IP ranges to scan, consider adding multiple discovery jobs rather than including all ranges in a single job.
• Subnets: Use this option to scan every IP address in a subnet. It’s recommended to scan at most a /23 subnet (512 addresses max). Scanning a subnet returns everything that responds to ping, so it’s best to only scan subnets where most devices are objects you want to monitor.
• IP Addresses: Use this option for a limited number of IP addresses that don’t fall in a range. Since a network discovery job can take a long time to complete, it’s recommended to use this option when you are first starting out.
• Active Directory: Use this option to scan an Active Directory Domain Controller. Using Active Directory for discovery is particularly useful for adding large subnets because the Orion Platform can use the devices specified in Active Directory instead of scanning every IP address.

Network device scanning can provide visibility into your network and the devices relying on it. This visibility can make it easier to detect issues when they arise and allows you to dig into the root causes of performance issues more quickly to reduce service interruptions to customers and maintain optimal productivity for end users. Since outages can be costly, quickly detecting and resolving issues can keep outages from occurring and help save money lost due to downtime.

There are also benefits to using a network device scanning tool instead of attempting to manually scan your network. Without an automated tool, network device scanning is often a manual and cumbersome process. A tool can help automate the discovery of devices on your network and can help you update network maps as the devices change.