Explore cutting-edge research on routing protocols and algorithms in this 20-minute conference talk from SIGCOMM 2020. Delve into new fundamental results in optimal path routing, examining the general formulation of optimal paths and various vectoring protocols like RIP, EIGRP, BGP, DSDV, and Babel. Understand the crucial role of isotonicity in optimal computations and learn about isotonic reduction techniques. Investigate the challenges of working with partial orders and multiple optimality criteria in routing. Discover how these concepts extend beyond multi-objective path problems and gain insights into partial-order routing protocols and algorithms. Enhance your knowledge of advanced networking concepts and their practical applications in modern routing systems.