802.1w - Spanning-Tree

802.1w know as Rapid Spanning-Tree is a great improvement over 802.1d Spanning-Tree.  802.1w operates with the same principle of Spanning-Tree however the convergence time is dramatically faster.

Another added benefit of 802.1w(Rapid Spanning-Tree) is the fact that single or multiple instances can be applied.  This can be done by applying RSTP with the Cisco proprietary PVST+ forming what's called RPVST+.

Just like 802.1d(Spanning-Tree) 802.1w(Rapid Spanning-Tree) chooses the Root Bridge based on the lowest Bridge ID.

Rapid Spaning-Tree Port Roles

• Root Port -  one port on each switch with best Root Path Cost to the Root Bridge
• Designated Port - ports on the Root Bridge
• Alternate Port - a different less desirable path to the Root Bridge and not the same as the Root Port
• Backup Port - a port that creates a redundant path to an already connected segment