Here is an Orion feature request that should be quite easy to implement.
ICMP echo replies not only return the response time of the polled device, but also the Time To Live of the packet.
By adding another column in the DB & recording the TTL, users could create an alert based on this value.
Normally the TTL should remain constant, but if it changes, then this indicates something has changed on the network between the poller and the polled node.
This could be an indication that routing has reconverged on the backbone, or the end device is now connected through a back-up connection.