Add or remove external networks connected to an edge gateway.
Click the Manage & Monitor tab, and click Organization vDCs in the left pane.
Double-click the organization vDC name to open the organization vDC.
Click the Edge Gateways tab, right-click the edge gateway name, and select Properties.
Click the External Networks tab.
(Optional) Select an external network from the top list and click Add to add the external network to the edge gateway.
Hold down Ctrl to select multiple networks.
(Optional) Select an external network from the top list and click Remove to remove the external network from the edge gateway.
Select a network to be the Default Gateway.
(Optional) Select Use default gateway for DNS Relay.
Click OK.