If e is not in the spanning tree, then, indeed, we dont need it. Multiple spanning tree multiple spanning tree protocol mstp network organized in regions regions have their own multiple spanning tree instances spanningtree topologies vlans are associated to mstis one common spanning tree cst for the entire network mstp based on rstp rapid stp. Spanning tree protocol stp is a layer 2 network protocol used to prevent looping within a network topology. Mstp uses bpdus to exchange information between spanningtree compatible devices, to prevent loops in each msti multiple spanning tree instances and in the cist common and. Spanning treeenabled switches go through a root election process based on bridge p rotocol. We have some costly hardware test tools, but if you company is implementing spanning tree protocol, the chances are you will have any of these tools in ypur lab. Understanding and configuring spanning tree protocol stp. Learn why do we need stp, spanning tree protocol and what it does to save your network from the loop and broadcast storm with lab example. Stp will identify if there are any loops, and then disable or block. One big disadvantage of stp is the low convergence which is very important in switched network. This will be discussed in lab 415 configuring multiple spanning tree protocol. Spanning tree protocol stp stp often accounts for more than 50 % of the configuration, troubleshooting, and maintenance headaches in real world campus networks especially if they are poorly designed. Before proceeding, save as stp configuration lab1working. Chapter 3 lab 31, spanning tree protocol stp default behavior.
Configuring pervlan spanning tree protocol free ccna. For a layer 2 network to function properly, only one active path can exist between any two stations. This topology makes more meaningful and challenging stp and vtp lab as compared to a single or switch pair topology. Stp spanning tree protocol explained with examples. Ciscos per vlan spanning tree pvst provides a significant step up from. Chapter 6 switching and spanning tree protocol freeccna 20150921t14. The possible states that a spanning tree port can be. The spanning tree protocol stp is designed to prevent layer 2 loops. Make sure switch grasshopper is the root bridge for vlan 40, switch butterfly should be the backup in case switch butterfly fails. The information in this document was created from the devices in a specific lab environment. To overcome this problem, in 2001, the ieee with document 802. Stp spanning tree protocol automatically removes layer 2 switching loops by shutting down the redundant links.
In the first chapter, you were introduced to bit of switching and switches. The multiple spanning tree protocol mstp is an stp variant that allows multiple and independent spanning trees to be created over the same physical network. Cisco ccnp switch advanced spanning tree certificationkits. This document descibes spanning tree protocol stp in a wireless environment. Im now able to create spanningtree protocol stp and vlan trunking protocol vtp lab using the famous switch triangle topology. As the name suggests, it creates a spanning tree within a mesh network of connected layer2 bridges typically ethernet switches, and disables those links that are not part of the spanning tree, leaving a single active path between any two network nodes. A redundant link is an additional link between two switches.
Switches running stp will build a map or topology of the entire switching network. In addition, you will design an addressing scheme based on host requirements. Root selection varies depending on the bid of each switch in your lab. Ranetcoresw to be the root bridge port fa02 of ranetsw2 to be in the blocking state please config spanningtree parameter on both ranetcoresw and ranetsw2 via its console to be as the requirement above. A redundant link is usually created for backup purposes. Observe and explain the default behavior of spanning tree protocol stp, 802. Cisco ccnp switch rapid spanning tree protocolrstp. He also developed several training and lab sessions for.
Pvst can load balance traffic at layer 2 of the osi model without causing a loop. Clear the configuration of a standalone switch to prepare it for a new lab. It treats a port as joining the active topology when it becomes. Spanning tree protocol in layer 2layer 3 environments. Spanning tree protocol stp is a layer 2 protocol that runs on switches.
Mst is commonly used in extremely large networks where running pvst would tax switch resources. I e e e s standards are rapid spanning tree protocol rstp and multiple stp mstp. This unsettling scenario just described is called a broadcast storm and can be avoided completely by using a layer 2 protocol sent among switches called the spanning tree protocol. What is spanning tree protocol with stp lab youtube. On each switch, display the spanning tree table with the show spanningtree command. Spanning tree protocol stp spanning tree protocol stp was developed to prevent the broadcast storms caused by switching loops. The multiple spanning tree protocol mstp and algorithm, provides both simple and full connectivity assigned to any given virtual lan vlan throughout a bridged local area network.
This lab will explain the functions of the ieee standard multiple spanning tree protocol also referred to as mst. Just like every coin has two sides, a redundant link, along with several advantages, has some disadvantages. Spanning tree enabled protocol ieee root id priority 32773 address 00. Stp is a layer 2 link management protocol that provides path redundancy while preventing loops in the network. The stp module transmits and receives bpdus bridge protocol data units which permit the module to learn the topology of the network and disable ports if necessary. Consider, city network as a huge graph and now plans to deploy telephone lines in such a. Spanning tree is basically used to find a minimum path to connect all nodes in a graph. In this lab, you will discover the spanning tree protocol, which is specified in the ieee 802. This lab has been developed as a packet tracer activity but can be completed with gns3 or real hardware. You use an algorithm called the spanning tree protocol just one of the. Configure and troubleshoot cisco spanning tree stp learn how to configure stp, portfast and bpduguard on cisco switches free ccna course handson lab networking fundamentals switching troubleshooting written by alessandro maggio. Spanning tree protocol online class with example and.
Root selection varies depending on the bid of each switch in your lab resulting in varying outputs. You can build the bpdu packet using the tool and test. Spanning treeenabled switches go through a root election process based on bridge p rotocol data unit. Chapter 6 switching and spanning tree protocol free ccna. Layer 2 switching and spanning tree protocol stp kumar. Once a proprietary protocol from dec, spanning tree protocol stp was standardized and blessed by the ieee specification, 802. The predecessor lan of b2 is a, so the link joining b2 to ashould stay. As jonathon mentioned, there are so many devices that combine. Stp configuration lab1 open the packet tracer scenario. You are not allowed to use the spanningtree root command.
Spanning tree protocol stp you are the network administrator of ranet, and would like. The spanning tree protocol run my experiment on geni. Configuring multiple spanning tree protocol mstp free. Ccnp switch chapter 4 lab 42 multiple spanning tree. It was first introduced as cst common spanning protocol then ieee introduced its advanced version as stp with specification ieee 802. Stp was created to avoid the problems that arise when computers compete for the ability to use the shared telecommunications path on a local area network. Spanning tree protocol typically runs on switches like the transition networks management aggregation converter smacf100. For an ethernet network to function properly, only one active.
When too many computers try to send at the same time, overall network performance is affected and can bring. Change the hello timer on all switches for vlan 10 to 4 seconds. Troubleshooting spanning tree protocol topology diagram addressing table device. Read how do all the operations happen and what are the chief components of the same. The purpose of this lab is to introduce the spanning tree protocol and how to configure priorities of core, distribution and access switches. The spanning tree protocol stp is a network protocol that builds a loopfree logical topology for ethernet networks. Lecture notes on spanning trees carnegie mellon school. In this lab scenario, you will configure a redundant network with vtp, multiple vlans, and stp. This protocol is used between switches, that will sometimes be called bridges in this lab.
Example of a bridged network with a loop, and the minimum spanning tree with the loop removed. Spanning tree protocol overview the plugandplay spanning tree protocol stp, a layer 2 protocol that ensures a loopfree topology in bridged lans, has been around for decades. Before proceeding, save as stp configuration lab 1working. Cisco saw the need for spanning tree on all vlans and create the proprietary pvst and. Spanningtree protocol is a link management protocol that provides path redundancy while preventing undesirable loops in the network. Spanning tree protocol stp determines the least cost path from the root bridge to other nodes in the networks. This lab will take youre understanding of spanning tree just a bit further. This lab is complete when all wired trunks are carrying traffic, and all three switches are participating in. The purpose of this lab is to introduce the spanning tree protocol and how to configure priorities of core, distribution and access switches appropriately. Stp spanning tree protocol step by step configuration. You already know that the layer 2 of the osi model deals with switching frames in the local network and that switches work at this layer. Spanning tree also allows a network design to include backup links to provide fault tolerance if an active link fails as the name suggests, stp creates a. The basic function of stp is to prevent bridge loops and the broadcast radiation that results from them. Spanning tree protocol stp is standardized as ieee 802.
Spanning tree protocol stp is a layer 2 protocol that runs on bridges and switches. Mst configuration is manual as there no current method to propagate this info as in vtp. This lab is a continuation from the earlier set up exercise, and the lab layout is identical. Stp overview stp is a layer 2 link management protocol that prov ides path redundancy while preventing loops in the network. Pervlan spanning tree protocol pvst is maintaining a spanningtree instance for each vlan configured in the network and uses ciscos proprietary isl trunking protocol. Lab 6 spanning tree protocol res 841 october 20 introduction in this lab, you will discover the spanning tree protocol, which is speci. All of the devices used in this document started with a cleared default configuration. Rapid spanning tree protocol rstp, which significantly reduces the convergence time after a topology change occurs in the network. Spanning tree protocol this document descibes spanning tree protocol stp in a wireless environment. Spanning tree enabled protocol ieee root id priority. Complex protocol that is generally poorly understood. When working with a switch that has been previously configured, any new commands entered will be merged. Stp configuration lab 1 open the packet tracer scenario. This section describes how spanningtree features work.