Check 1: Refresh

Right click discovery and choose "refresh".

Check 2: Check router or switch

The Gatekeeper is powered using PoE+(IEEE802.3at)

Is the router/switch a PoE+ IEEE802.3at device?

Check 3: Are CortexClient and the Gatekeeper in the same network?

Make sure the Gatekeeper and CortexClient are connected to the same network.

If necessary connect a laptop to the same router/switch as the Gatekeeper.

Check 4: Networkcable

A Cat5E UTP Cable or higher is required, with a maximum length of 50 meters.

Changing the network cable can be a good choice. Often connectors are crimped manually on the spot. A self crimped connector can be crimped wrongly.