Link Controller monitor issue

Hello,

 

I'm using Link controller in order to monitor the two upstream internet access.

 

I have two public subnet A & B, subnet A is only routed through ISP1 and subnet B is only routed through ISP2.

 

My issue is that Link controller can only monitor LAN interface of each ISP, so if the WAN interface of the ISP goes down the BigIP don't detect it and continue resolve DNS queries with the faulty subnet

 

My question is there a way to monitor WAN interface of ISP to make sure that DNS works properly. As what LTM does with the "default gateway pool function"

 

Thanks for your help

 

Regards

 

Lotfi