Expedite IP discovery

Use the Expedite IP Discovery action to address delayed endpoint IP discovery. To expedite IP resolution, the Switch plugin queries the ARP tables of designated, adjacent, L3-enabled network devices.

The Expedite IP Discovery action is the only action that is available for use with plugin-managed firewalls, Linux routers and SD-WANs.

Consider using the action if you identify a high failure rate of actions that is due to the IP address of the detected endpoint being unknown (unresolved).

Delayed endpoint IP discovery can be caused by any of the following reasons:

Endpoint is connected to an L2 network device
Connecting network device does not permit IP discovery
No configured SPAN port (traffic mirroring is turned off)
Misconfigured SPAN port
Regular polling of connecting network device or an adjacent upstream device is too slow

To use the action, verify the following:

The detected endpoints are connected to an access switch that is configured in the Switch plugin.
In the Switch plugin configuration, the access switch is assigned to a minimum of one Connectivity Group.
At least one L3-enabled network device is configured in the Switch plugin that:
- has the option Read: IP to MAC Mapping enabled.
- has the option Allow IP Discovery from Connectivity Group enabled.
- is assigned to the same Connectivity Group as the access switch.
- The ip2mac_aggregation_interval advanced configuration flag is configured with the appropriate interval.

A Connectivity Group defines a group of adjacent network devices (any combination of L2, L3-enabled, L2/L3-enabled). When the access switch, to which detected endpoints are connected, cannot be used to resolve endpoint IP addresses, and the Switch plugin performs the Expedite IP Discovery action:

The plugin queries the Connectivity Group’s L3-enabled network devices that are configured to Allow IP Discovery from Connectivity Group.
The plugin obtains their ARP table data (IP to MAC mapping) and resolves detected endpoint IP addresses.