Summary: Consensus Routing: The Internet as a Distributed System
John P. John
Internet routing protocols (BGP, OSPF, RIP) have tra-
ditionally favored responsiveness over consistency. A
router applies a received update immediately to its for-
warding table before propagating the update to other
routers, including those that potentially depend upon the
outcome of the update. Responsiveness comes at the cost
of routing loops and blackholes--a router A thinks its
route to a destination is via B but B disagrees. By favor-
ing responsiveness (a liveness property) over consistency
(a safety property), Internet routing has lost both.
Our position is that consistent state in a distributed sys-
tem makes its behavior more predictable and securable.
To this end, we present consensus routing, a consistency-