The Trace tool will perform an ICMP “trace route” from MxToolBox to any host you want to check. Trace routes will show you the router “hops” required to reach a destination along with delay times. Trace Routes work by sending out multiple ICMP echo requests with different “Time to Live” (TTL) values. For example, sending a request with a TTL of “2” will cause the second external router (hop) to reply with an ICMP Time Exceeded message, which let’s us know where that second hop is. Note that some ISPs configure their routers to not respond to ICMP, so those hops will be shown as blank (* * *).