The impact of multi-homing on network reliability and stability: a case study

The number of multi-homed user sites has been rapidly increasing in recent years, where a campus or company network is connected to multiple Internet service providers´ networks to improve Internet service reliability. In this paper, we examine the impact of multi-homing via BGP on routing stability and network reliability. More specifically, we compare single-homed prefixes with multi-homed prefixes in terms of the number of routing update messages and the duration of unreachability. Our results show that, on average, single-homed prefixes both generates fewer routing updates than multi-homed prefixes, and provide higher reliability than 97% of multi-homed prefixes (which have a low degree of multi-homing). These results suggest the need to further improve BGP´s stability to enable Internet users to gain the expected reliability benefit from multi-homing.