| Messy traceroutes make the helpdesk phone ring. Messy architecture is worse! There's two ways to deal with the "messy traceroute problem": 1. looking glasses - use them to compare traceroutes, point people at them, couple them with ample notes on how to interpret the results of multiple traceroutes launched from a variety of sources utility & education leads to wisdom, and away from "nuisance" phonecalls. everyone wins. 2. if you'd rather stem the tide of calls without helping your users much, break traceroute. a/ make it not work in practically all cases on the grounds that the catharsis of its spurious reputation as a powerful diagnostic tool is LONG overdue b/ intercept low-ttl packets and return them with "better" information some MPLS people have documented ways to do this, even it works, although if you do it some ways, you generate media attention. check your nanog records Basically, arguing that the routing system should carry around even more information is backwards. It should carry less. If IXes need numbers at all (why???) then use RFC 1918 addresses and choose one of the approaches above to deal with questions about why 1918 addresses result in "messy traceroutes." Fewer routes, less address consumption, tastes great, less filling. Sean.