By default, all IP addresses outside of locally-monitored broadcast domains are aggregated at an incoming router. To discover the devices behind these routers and view metrics associated with them, you can create a custom device. Custom devices are manually created in the Discover appliance and can be configured to collect metrics for traffic observed across multiple IP addresses and ports. Custom devices are useful for tracking device behavior outside of your local broadcast domain.
|Important:||Custom devices affect ExtraHop system performance.|
Here are some important considerations about custom devices:
- Avoid creating multiple custom devices for the same IP addresses or ports. Custom devices that are configured with overlapping criteria might degrade system performance.
- Avoid creating a custom device for a broad range of IP addresses or ports, which might degrade system performance.
- Custom devices are counted against the device limit for your appliance. A device limit is the total number of devices that the Discover appliance can fully analyze. For more information, see View the device limit and device counts.
- Custom devices can only be created on a Discover appliance.
- Custom devices appear in the ExtraHop system after traffic is observed that matches the IP address and port criteria that you specify.
The following steps show you how to create a custom device:
- Log into the Web UI of the Discover appliance.
- Click the System Settings icon at the top of the page.
- Click Custom Devices.
- On the Custom Device Settings page, click New. The Custom Device Configuration dialog box opens.
- Type a name for your custom device.
Type a unique identifier.
If you leave this field blank, an ExtraHop ID is automatically assigned to your custom device.
- Type a description.
Click Add Criteria to specify the IP addresses and ports
that you want to collect metrics for. You can provide a combination of criteria
to collect metrics across multiple devices or for a single device. You do not
need to complete each field.
- In the IP Address field, type an IP address or a CIDR notation.
- In the Source Min Port field, type a minimum source port.
- In the Source Max Port field, type a maximum source port.
- In the Destination Min Port field, type a minimum destination port.
- In the Destination Max Port field, type a maximum destination port.
Note: You cannot add VLAN criteria to a new custom device, or to an existing custom device that does not already have VLAN match criteria. Contact ExtraHop Support for more information.