To prevent the delay when connecting hosts to a switch and during some topology changes, Rapid STP was developed and standardized by IEEE 802.1w, which allows a switch port to rapidly transition into the forwarding state during these situations.
Rapid Spanning Tree Protocol (RSTP), which provides for faster spanning tree convergence after a topology change. Standard IEEE 802.1D-2004 now incorporates RSTP and obsoletes STP. While STP can take 30 to 50 seconds to respond to a topology change, RSTP is typically able to respond to changes within 3*Hello (default is 6 seconds).
RSTP bridge port roles:
* Root - A forwarding port that is the best port from Nonroot-bridge to Rootbridge * Designated - A forwarding port for every LAN segment * Alternate - An alternate path to the root bridge. This path is different than using the root port. * Backup - A backup/redundant path to a segment where another bridge port already connects. * Disabled - Not strictly part of STP, a network administrator can manually disable a port
RSTP is a refinement of STP and therefore shares most of its basic operation characteristics.
if Rapid STP is used on both C6500 convergence time should be just the time to exchange BDPUs to perform the handshake: one side proposes its port as the designated port for segment the other side can agree on this or not.
no timers are involved and here is the great advantage of Rapid STP.
When adding a new link to an existing topology, switches use the so called synchronization wave: all links are freezed and on one single link the change is proposed to the other side.
Cisco implementation should use this freeze of other ports only when considering the root port.
It is very important to declare edge ports with spanning-tree portfast to reduce the total numbers of ports involved in a synchronization to achieve real fast convergence.
Hi everyone, I would like to thank you in advance for any help you can provide a newcomer like myself!
Im studying the 100-105 book by Odom and am currently on the topic of Port security. I purchased a used 2960 and I'm trying to follow a...
While deploying a number of 18xx/2802/3802 model access points (APs), which run AP-COS as their operating platform. It can be observed on some occasions that while many of their access points were able to join the fabric WLC withou...
I am going to design and build an LAN network under a tunnel underground with long distance between the switches.
I will have 2 Catalyst switches and 8 Industrial IE3000, and they will be connected with fiber.
For now I am planning on use Layer-2 s...