Hello @braham_ilg You are not doing anything wrong , it is just because of the  MX is connected through a switch, the WAN port still shows link-up even when the ISP device (CPE) is unplugged. So the MX waits for its probes (ping/DNS/HTTP) to fail before switching, which takes time. If you want the faster failover then directly connect the MX WAN port to ISP CPE or you can set the failover mode the immediate in the MX.  ... View more