CCIE: STP (802.1d)
So, first a little history on Spanning tree protocol (STP). Based on an algorithm created by Radia Pearlman in 1985. http://en.wikipedia.org/wiki/Radia_Perlman Became a standard IEEE protocol in 1990. Still widely deployed. Flavors of spanning tree. 802.1d (ieee), 802.1w (rapid), and 802.1s (mst). Evolution of STP, Cisco vPC (2-way non blocking, still requires STP) and Fabric Path (eliminates STP completely). TRILL is a standardized version of Fabric Path. Both TRILL and Fabric Path utilize a link state protocol (IS-IS) as their loop prevention method. Specific Cisco enhancement to 802.1d (prior to 802.1w):…