LAG Bridge Mode

Hi,

Is it possible to deploy XG230 with LAG in Bridge Mode? We have a customer where we arn´t  responsible for the network infrastructure. The customer now has gotten a second MPLS connection for redundancy and the failover is managed by a L3 Cisco via HSRP. 

I now want to deploy 2 XG230 (Bridge Mode / HA active passive) between the L3 and the  MPLS modems. So i need some advice how to deploy the XGs inthis scenario with a minimal Networkfootprint.

1. My first thougt was to bridge on connection through XG1 and the second through XG2 and let the switch do the rest.  --> But this isn´t active passive and the costumer needs a buy a license he do not need.

2. The second thought was to bridge booth MPLS connections through booth XG´s and let switch do the rest unless the XG has a problem. But i´m not sure that this is working correctly.

3. Maybe we can use LAG but in this case the XG is responsible for the failover. Which from my perspective i´m totally okay with but it´s out network  And is it possible to bridge LAG through the FW. For Example: LAG (2Interfaces extern) --> 1 Interface intern or 2. LAG extern --> 2 Interfaces intern and the switch can do the failover anyways? 

I hope someone can ask me the question or maybe can put me in the right direction.

regards

Ecrook