mon ( http://mon.wiki.kernel.org/index.php/Main_Page ) comes with traceroute.monitor
It keeps a state file of current routes and logs only changes. You can specify equivalent hops, hops to ignore, StopAt addresses, and UnexpectedHops. Since it is part of mon, it is easy to alert on a route change. The IgnoreHop feature was probably added after the mon release. I can provide a newer version if IgnoreHop would be useful. Jon
