Rfc 7727 spanning tree protocol stp application of the. Even more confusing some whitepapers on ciscos website will define the. Stp overview stp is a layer 2 link management protocol that prov ides path redundancy while preventing loops in the network. Information technology telecommunications and information exchange between systems local and metropolitan area networks common specifications part 3. In discussions about stp, the term root is used to describe two concepts. Spanning tree protocol stp is a protocol which prevents layer 2 loops. In other words, there is no way to interconnect multiple virtual switches, thus the network cannot be configured to introduce loops. To prevent loops, spa places some interfaces into forwarding state and some interfaces into blocking state. Like it name, rstp rapid spanning tree protocol is the fastest converged version of stp. Many people struggle with stp so in this video, we try to break it down as much as possible. Mstp multiple spanning tree protocol can map a group of vlans into a single multiple spanning tree instance msti. The main purpose of stp is to ensure that you do not create loops. Root bridge is a switch in a single vlan or whole topology according to the type of stp standard used which is responsible for distributing bpdus and block the least redundant port.
Spanning tree protocol in layer 2layer 3 environments. Spanning tree also allows a network design to include backup links providing fault tolerance if an active link fails. For a layer 2 network to function properly, only one active path can exist between any two stations. Stp uses a concept with path costs there may be a better topology, though, depending on the selection of the rb. Furthermore, the administrator can define alternate paths within a spanning tree. Presentation aqseamanmergedspanningtreeprotocols1108. Many people struggle with stp so in this video, we try to break it down as much. Stp will identify if there are any loops, and then disable or block.
The s stands for segmenting, the t for targeting and the p for positioning. Stp allows bridges and switches to communicate with each other so. On each switch, display the spanning tree table with the show spanningtree command. Cisco developed, implemented and published the per vlan spanning tree pvst proprietary protocol using its own proprietary inter switch. How stp works video by sikandar shaik dual ccie rs.
The basic function of stp is to prevent bridge loops and the broadcast radiation that results from them. Stp creates a tree structure of loopfree leaves and branches that spans the entire layer 2 network. Spanning tree protocol stp was developed to prevent the broadcast storms caused by switching loops. Understanding spanning tree protocol this section describes how spanningtree features work. Spanning tree protocol this document descibes spanning tree protocol stp in a wireless environment. Algorithm that creates a loopfree logical topology. In this video you will be learn, how to configure spanning tree protocol step by step spanning tree protocol configuration by example. 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. The spanning tree protocol stp is a network protocol that builds a loopfree logical topology in, the ieee introduced rapid spanning tree protocol rstp as w. Stp enables switches to become aware of each other so that they can negotiate a loopfree path through network.
The spanning tree protocol stp is a network protocol that builds a loopfree logical topology. On the new version of the cisco ccent 100101, cisco icnd2 200101 and ccna 200120 exams cisco has made the questions much, much, harder than previous versions of the ccna exam. Understanding issues related to intervlan bridging pdf. Spanningtree protocol is a link management protocol that provides path redundancy while preventing undesirable loops in the network. Stp, rstp, and mstp page 3 overview of spanning trees overview of spanning trees the concept of the spanning tree protocol was devised to address broadcast storming.
Spanning tree protocol routeros is capable of running bridge interfaces with rmstp support in order to create a loopfree and layer2 redundant environment. Different root switches and different stp parameters can be individually configured for each msti. Stp spanning tree protocol step by step configuration. Spanning tree protocol stp was developed to prevent the broadcast. Presentation et configuration du protocole spanning tree. In this document, provider edge pe devices in a redundancy group rg running iccp are used to offer multihomed connectivity to spanning tree protocol stp networks to improve availability of the stp networks. How does stp decides in which state to port will be placed. This is because layer 2 ethernet frameshave no time to live or time out mechanismbuilt into the frame. Download pdf stp spanning tree protocol step by step configuration tutorial when sw3 start receiving inferior bpdus at its interface from sw2, switch3 would ignore the inferior information until the bpdus stored with the blocked port expires max age timer 20 seconds. Spanningtree operation is transparent to end stations, which cannot detect whether they are connected to a single lan segment or to a. Ccna stp tutorial by mukesh all is well channel thind shows stp configuration in packet tracer in hindi or how to configure stp spanning tree protocol in hindi. Stp spanning tree protocol explained with examples.
Introduction to spanning tree protocol contemporary controls. Spanning treeenabled switches go through a root election process based on bridge p rotocol. Spanning tree protocol stp is a layer 2 protocol that runs on bridges and switches. 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. It is always recommended to manually set up each bridges priority, port priority, and port path cost to ensure proper layer2 functionality at all times. 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 lan. Going through this process allows a business owner and marketing consultants or employees to formulate a. Calculate the same spanning tree topology with the same. Abcs of spanning tree protocol contemporary controls. Lecture notes on spanning trees carnegie mellon school.
Understanding spanning tree protocols stp, rstp, mstp. Today we are going to cover an example of a spanning tree protocol scenario type question that you might see on your cisco ccent or ccna exam. Unlike other types of stps, mstp can block ports selectively by vlan. This concept is what makes up the core of the backbonefast engine. Spanning tree protocol stp spanning tree protocol stp was developed to prevent the broadcast storms caused by switching loops.
Root selection varies depending on the bid of each switch in your lab. Which means, the spanning tree protocol is applied separately for a set of vlans instead of the whole network. Prerequisites for implementing multiple spanning tree protocol information about implementing multiple spanning tree protocol. Understanding spanning tree protocols on a qfabric system overview of spanningtree protocols qfx series switches provide layer 2 loop prevention through spanning tree protocol stp, rapid spanning tree protocol rstp, multiple spanning tree protocol mstp, and vlan spanning tree protocol vstp. Stp spanning tree protocol automatically removes layer 2 switching loops by shutting down the redundant links. Configuring stp protocol techlibrary juniper networks. For an ethernet network to function properly, only one active.
The main purpose of stp is to ensure that you do not create loops when you have redundant paths in your network. Every segment is given a path cost as per the following table from ieee 802. One of the stp version is rstp rapid spanning tree protocol. In this example, we will configure rstp rapid spanning tree protocol with packet tracer. Switches running stp will build a map or topologyof the entire switching network. The problem is that when we create redundancyat a layer 2 level of our networks,we create loops that traffic will traverse indefinitely. Stp is a layer 2 link management protocol that provides path redundancy while preventing loops in the network. Understanding and configuring spanning tree protocol stp on. With the advent of layer 3 switching in lan environments, bridging now competes.
In this post, instead of detaily talk about stp spanning tree protocol, we will focus on a basic switching loop topology and how stp mechanism helps to avoid this switching loop. Understanding and configuring spanning tree protocol stp. The multiple spanning tree protocol mstp and algorithm, provides both simple and full. Principles of imperative computation frank pfenning lecture 24 november 18, 2010 1 introduction. Digital equipment corporation created a protocol called spanning tree protocol stp to prevent broadcast storms and network loops at layer 2. Ccna 200301 how to configure spanning tree protocol. To allow management of active topology for rstp, mstp, or spb means of assigning values to the following are required. The first thing to point out is that this article focuses on the original version of stp that is covered in ieee 802. Stp uses the spanningtree algorithm spa to create a topology database of the nework.
What is stp marketing stp marketing is a threestep approach to building a targeted marketing plan. Root selection varies depending on the bid of each switch in your lab resulting in varying outputs. 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. Concepts description of the technology stp operation task stepbystep instructions verify troubleshoot stp path cost automatically changes when a port speedduplex is changed troubleshoot commands command summary related information introduction spanning tree protocol stp is a layer 2 protocol that runs on bridges and switches. Multiple spanning tree protocol or multiple instance spanning tree protocol. Choose from 102 different sets of spanning tree protocol ccna flashcards on quizlet. Pdf spanningtree protocol stp has nowadays been implemented by most manufacturers in order to avoid loops in bridged networks. The interchassis communication protocol iccp supports an inter chassis redundancy mechanism that is used to support high network availability. Multiple spanning tree protocol mstp is a spanningtree protocol used to prevent loops in bridge configurations.
Prerequisites for implementing multiple spanning tree protocol. In practical scenario, redundant links are created to avoid complete network failure in an event of failure of one link. If e is not in the spanning tree, then, indeed, we dont need it. Also called common spanning tree cst, it assumed one spanningtree instance for the entire bridged network, regardless of the number of vlans. Spanning tree protocol stp is used to make a loop free network by monitoring the network to track all the links and shut down the least redundant ones. Switches running stp will build a map or topology of the entire switching network. Effects of remote user authorization on user accounts52 authorization for groupbased remote user accounts53. The spanning tree algorithm itself is defined by the ieee standard 802. Learn spanning tree protocol ccna with free interactive flashcards. Spanning tree protocol explained step by step youtube.