IETF 80 - Tutorials

Prague, Czech Republic
March 27-April 1, 2011

Routing, Bridging, Switching

Presented by: Radia Perlman

Sunday, March 27, 2011 - 15:00-16:50
Room: Congress Hall II

This tutorial shows how traditional layer 3 intradomain routing algorithms work, and explains why layer 2 forwarding ("bridging") was invented. We discuss the spanning tree algorithm, which forms the basis of modern Ethernet, and show its disadvantages. We also discuss why, despite its disadvantages, spanning tree Ethernet is still so popular. Then we discuss the new IETF standard, TRILL (TRansparent Interconnection of Lots of Links), and how it gives the best of both worlds; the ease of configuration of Ethernet, and the optimal path routing provided by layer 3.