Operations Manager discovers network devices by running discovery rules that the Operations Manager Administrator configures. Network discovery rules include the following information:
- IP address or FQDN of the devices that you want to discover.
- The SNMP (Simple Network Management Protocol) version used by each device. Operations Manager supports SNMP v1, v2, and v3.
- The SNMP community string of any SNMP v1 or v2 compatible devices to be discovered.
- User name, context, authentication protocol, authentication key, privacy key, and privacy protocol for each SNMP v3 device.
- The management server that will monitor the discovered network devices.
When performing network discovery, any firewalls between the Operations Manager management server and the network devices to be discovered must allow SNMP (UDP) and ICMP bidirectionally. SNMP usually uses 161 (UDP) and 162 (TCP/UDP). If you are going to be discovering devices that use SNMP v1 or v2, you’ll need to configure the Run As account to use for this purpose. You can do this before creating the discovery rule, or during the discovery rule creation process.
To create a network discovery rule, perform the following steps:
1. Right-click the Network Management node in the Administration workspace of the Operations Manager console, and click Discovery Wizard.
2. On the Discovery Type page of the Computer And Device Management Wizard, click Network Devices, as shown in Figure 1, and click Next.
FIGURE 1 Network devices
3. On the General Properties page, shown in Figure 2, provide the following information:
- The name for the rule. An informative name for the Rule.
- The management server from which network discovery will be performed.
- The resource pool. You can create a new resource pool, or select an existing resource pool that will be responsible for monitoring discovered network devices.
FIGURE 2 Network Discovery rule
4. On the Discovery Methods page, shown in Figure 3, choose between Explicit Discovery and Recursive Discovery. You should select Explicit Discovery when you know the address of each network device that you want Operations Manager to manage. Recursive Discovery provides a more thorough discovery of network devices, but this process is likely to take longer and is likely to discover devices that you may not be interested in having Operations Manager monitor.
FIGURE 3 Explicit Discovery
5. If you are discovering devices that support SNMP v1 or SNMP v2, either select an existing Run As account, or create a new Run As account for this purpose. This Run As account includes the SNMP v1 or v2 community string.
6. On the Devices page, shown in Figure 4, you can either add the devices that you want to discover manually, or import them from a text file that contains a list of IPv4 addresses.
FIGURE 4 Specify devices
7. When adding devices manually, provide the following information as shown in Figure 5:
- IPv4 address or FQDN of the device.
- Access mode. This can be ICMP, SNMP, or ICMP and SNMP. If you choose ICMP and SNMP, the device must be accessible using both protocols.
- Port number. The default is UDP port 161, but if you are using another port for SNMP you can change this.
- SNMP version. This allows you to specify whether to use SNMP v1 or v2, or SNMP v3. If using SNMP v1 or v2, specify the Run As account that contains the community string.
FIGURE 5 Add a device
8. If adding an SNMP v3 device, you will need to add the FQDN or IP address, as well as an SNMP v3 Run As account that includes User Name, Context, Authentication Protocol, Authentication Key, Privacy Protocol, and Privacy Key.
9. If you are creating a recursive discovery rule, you can configure filters based on IP address range. You can also configure exclusions on a per IP address basis.
10. On the Schedule Discovery page, specify how often to run the network device discovery rule. Figure 6 shows this page.
FIGURE 6 Network discovery schedule
11. On the Summary page, review the settings, and click Create.
You can confirm successful discovery of network devices by viewing the Network Devices node, under Network Management in the Administration workspace of the Operations Manager console.
