hi,if you ping 8.8.8.8 with source ip 172.16.10.1 while the line is down, you get replay?if not you should configure the ip sla 1 with source ip address.or try to track the line ip addrees (over the XTM).

Hi,Your sla should look like this:ip sla 1 icmp-echo 172.16.10.10 frequency 10ip sla schedule 1 life forever start-time now ip sla 2 icmp-echo 172.16.100.2 frequency 10ip sla schedule 2 life forever start-time now  

You need to put on ip sla 1 ip address 172.16.10.10. And for ip sla 2 ip address 172.16.100.2. You got in to loop because you track 8.8.8.8 that become alive on the other route. Yaron.