Changing the settings of the traffic’s source physical interface and moving it to the bridge

On each firewall that is part of the GRETAP tunnel:

  1. In the Configuration > Network > Interfaces module, double-click on the source physical interface of the traffic that needs to go through the tunnel.
    In the example shown, this will be the in interface.
  2. In General settings This interface is field, select External (public).
  3. In Address range > Address range field, select Address range inherited from the bridge.
  4. In Address range > Bridge field, select the bridge created earlier (new_bridge1 in the example).
    The interface is automatically moved to the bridge new_bridge1.
  5. Go to the Advanced properties tab.
  6. In Routing by interface, select Keep initial routing.
    A Keep VLAN IDs check box appears. Select it.
  7. Click on Apply to confirm the creation of the GRETAP interface.