Date Added: Jan 2010
The Internet's routing architecture was designed to have a clean separation between the intradomain and interdomain routing protocols. However, the appropriate division of labor between these two tiers becomes unclear when an Autonomous System (AS) has interdomain routes to a destination through multiple border routers a situation that is extremely common today because neighboring domains often connect in several locations. Unfortunately, this evolution in Internet structure has made it increasingly susceptible to unforeseen interactions between the two routing protocols. Authors believe that the current mechanism of early-exit or hot-potato routing where each router in an AS directs traffic to the closest border router based on the intradomain distances is convoluted, restrictive, and sometimes quite disruptive.