GTM Link Monitoring behind firewall

Hi,anyone has experience/solution for monitoring ISP links with GTM(Private IP) behind firewall?

 

MY GTM is place in DMZ behind a firewall with 3 router connecting to 3 different ISP. Will it be possible

 

for the GTM to be able monitor the link and stop responding the ISP ip range if the ISP link is

 

down?

 

Thanks in advance

 

Bob