Besides cellular connectivity, the gateway can achieve internet connectivity through the embedded Ethernet port to communicate with Centaur cloud. The available Ethernet port connectivity can also be used for remote troubleshooting by Centaur team. In the edge case that cellular signal is unavailable or too weak, Ethernet internet connectivity may be required for firmware update purposes (to download update packages) or for uploading large batches of cached sensor data in case there has been no internet connectivity for a long period.  
To ensure waterproofness of the electronics inside the gateway, the Ethernet along with other ports are protected with a stainless-steel cover fixed with six screws at the bottom of the gateway case. To remove the cover you will need a 2.5mm allen wrench to unscrew the six screws as shown in the next picture: 

Note: Once the cover is removed, the case loses its waterproofness, therefore, it is advised to be placed indoors.  

For internet connectivity, the Ethernet port closer to the USB ports must be used: 

Once the ports are exposed, connect an Ethernet cable to the rightmost (closest to the USB ports) Ethernet port of the gateway.