A network reference model serves as a blueprint, detailing standards for how protocol communication should occur. One of the topics on the ccna rs version 3 exam is spanning tree protocol stp. Spanning tree protocol ccnax 200120 ccna practice tests. Ccna tutorials are available to pass the ccna exam. Spanning tree protocol this document descibes spanning tree protocol stp in a wireless environment.
Here you can find all materials needed to study for your ccna. Ccna tutorials are available on various websites and offline books. Understanding and configuring spanning tree protocol stp. Spanning tree protocol stp finds the redundant link by the spanning tree algorithm. The main purpose of stp is to ensure that you do not create loops when you have redundant paths in your network. For a layer 2 network to function properly, only one active path can exist between any two stations. Rapid spanning tree protocol rstp one big disadvantage of stp is the low convergence which is very important in switched network. Configure and troubleshoot cisco spanning tree stp. Protocols are covered in great detail in other guides. This webcast shows you the stp topics for which youre responsible on the ccna rs 200125 or icnd2 200105. Ccna training spanning tree protocol stp tutorial network.
To finds a redundant link, it uses an algorithm, known as the sta spanningtree algorithm. The transmitting switch port id, will be discussed later 2. The following figure shows a basic network with simplified 4digit mac. Stp spanning tree protocol step by step configuration. Ccnp switch chapter 4 exam answers version 7 score 100%.
Stp overview stp is a layer 2 link management protocol that prov ides path redundancy while preventing loops in the network. Spanning tree protocol stp for ccna rs 200125 and icnd2 200105 candidates duration. The problem is that when we create redundancyat a layer 2 level of our networks,we create loops that traffic will traverse indefinitely. 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. Types of spanning tree protocol stp explained ccna. These looping frames would cause network performance problems. Lesson 78 how to configure cisco ios zone based firewall. While most people like the effects of redundancy, the redundancy can cause problems at layer 2. Many people struggle with stp so in this video, we try to break it down as much as possible. To enable spanning tree, connect to your switch and type spanningtree mode while in global configuration mode. Stp is on by default, but it only really comes alive when we have two or more switches interconnected with each other. Spanning tree protocol stp is a layer 2 network protocol used to prevent looping within a network topology. Here is an example network consisting of two computers connected together. The redundant link creates a loop between switches.
The site was designed to help you pass the ccna exam 200125, but it can also be used as a reference site for anything networking related. Cisco developed, implemented and published the per vlan spanning tree pvst proprietary protocol using its own proprietary inter switch. Spanning tree protocol, or stp, prevents switching loops in the layer 2 portion of our network. Spanning tree protocol stp is a network protocol designed to prevent layer 2 loops. Ccna training spanning tree protocol stp tutorial free download as pdf file. In modern networks this spanning tree protocol stp convergence time gap is not acceptable and cisco enhanced the. Stp is a layer 2 link management protocol that provides path redundancy while preventing loops in the network.
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. Another version of spanningtree is able to calculate a topology for each vlan. Spanning tree protocol stp spanning tree protocol stp was developed to prevent the broadcast storms caused by switching loops. You should have deep knowledge in basic networking, tcpip and ipv6 before start learning ccna routing and switching. Stp is a layer 2 protocol that runs on switches and bridges, the purpose of stp is to remove switching loops. Rapid spanning tree protocol rstp, which significantly reduces the convergence time after a topology change occurs in the network. Spanning tree protocol stp is a layer 2 protocol that runs on bridges and switches. Here you will find answers to spanning tree protocol questions.
Spanning tree protocol stp is a big topic on the ccna exam. It is desirable to have redundant links in a switched lan so that a single link failure cannot interrupt normal operation of the network. Stp spanning tree protocol explained with examples. Free cisco certified network associate ccna online. Mar 02, 2019 cisco developed, implemented and published the per vlan spanning tree pvst proprietary protocol using its own proprietary inter switch. Many people struggle with stp so in this video, we try to break it down as much. Nov 16, 2016 one of the topics on the ccna rs version 3 exam is spanning tree protocol stp. Therefore, lans use spanning tree protocol stp, which allows the redundant lan links to be used while preventing frames from looping around the lan indefinitely through those redundant links. Spanning tree protocol stp for ccna rs 200125 and icnd2. Free cisco certified network associate ccna online tutorials and study guides. Switches running stp will build a map or topology of the entire switching network. Network reference models were developed to allow products from different manufacturers to interoperate on a network.
Spanning tree protocol stp is a data link layer layer 2 protocol that is used to discover and maintain a valid loopfree path for the switched network. Cisco ccna spanning tree protocol tutorial jared heinrichs. If you have not yet registered, you will be prompted to register, before proceeding to access this content. However, providing redundant paths between segments causes packets to be.
Cisco ccna spanning tree protocol stp spanning tree protocols stps main task is to stop network loops from occurring on your layer2 network bridges or switches. Stp spanning tree protocol automatically removes layer 2 switching loops by shutting down the redundant links. Spanning tree protocol stp was developed before switches were created in order. So therefore, if there is a tie in our value with spanningtree protocol, there has to be a tiebreaker mechanism.
There are many pdf books also available some of them are paid. When the network is converging on a topology change, no traffic is forwarded to or from any of the network bridges and switches. The golden rule of spanningtree protocol is lower is better. If you dont know what the layer 2 switching loop is and how it works, i suggest you take a pause here and check the first of this tutorial first. This lesson explains what is rapid spanning tree protocol rstp tutorials and cisco enhanced the original spanning tree protocol stp ieee d. The switch with the lowest switch id will become the root bridge. How stp works video by sikandar shaik dual ccie rs. Blocking during blocking state, the port is listening to and processing bpdus after 20 seconds, the switch port changes from the blocking state to the listening state. With the advent of layer 3 switching in lan environments, bridging now competes.
The message that a switch sends, allowing the formation of a loop free logical topology, is called a bridge protocol data unit bpdu. Spanning tree protocol is a link management protocol that provides path redundancy while preventing undesirable loops in the network. Tutorial on stp, spanning tree protocol algorithm, which finds the minimum spanning tree for packet forwarding between switches in a network. All switches from cisco ship with spanning tree protocol stp enabled by default, but if stp is misconfigured for any reason, you can easily enable it. Spanningtree protocol is a link management protocol that provides path redundancy while preventing undesirable loops in the network. Introduction to spanningtree spanningtree is a protocol that runs on our switches that helps us to solve loops. It vigilantly monitors the network to find all links, making sure that no loops occur by blocking any redundant ones. Lesson 76 c3pl cisco common classification policy language, class map, policy map and service policy. A redundant link is usually created for backup purposes.
Ccna tutorials a perfect guide to getting ccna certified. No particular configuration is needed to attain this. This document descibes spanning tree protocol stp in a wireless environment. Spanning tree is basically used to find a minimum path to connect all nodes in a graph. The spanning tree admin march 2, 2019 march 2, 2019 no comments on cisco rstp tutorial pdf. Infrastructure devices might also learn endstation mac addresses on multiple layer 2 interfaces.
Spanning tree protocol stp was developed to prevent the broadcast storms caused by. Path of packet i count this as a technology topic because it involves the forwarding mechanisms for the various catalyst platforms, spanning tree protocol, multicast, and quality of service. 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. Ccna tutorials are available to pass the ccna exam 200125, icnd1 and icnd2. We will focus on spanning tree protocol stp configuration and verification commands in this tutorial, as implemented on cisco switches. For an ethernet network to function properly, only one active.
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. Spanning tree protocol explained step by step youtube. Spanning tree protocol stp is standardized as ieee 802. This is very necessary in large networks that are designed to have redundancy like backup switches and multiple paths across the network. Vlan0005 spanning tree enabled protocol ieee root id priority 32773 address 00. 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. This content is only accessible by registered users. Cisco ccna spanning tree protocol tutorial in most networks larger than your typical smb switched networks, there will be path redundancy. Spanning tree protocol introduction 11012015 jonathan leave a comment this is the first in a series of posts on spanning tree, in this post i will be describing the need for spanning tree protocol stp in modern lan environments.
Introduction to stp, spanning tree protocol, broadcast storm, topological loop, switch macaddress table corruption,stp pdf file download, pdf file download, ethernet bridge, ethernet switch,layer 2 topological loop,ieee 802. Free cisco certified network associate routing and switching ccna routing and switching online tutorials and study guides. What is spanning tree protocol stp lesson 102 what is bridge protocol data unit bpdu frame. Rstp significantly reduces topology reconverging time after a. Cisco networking allinone for dummies add to cart amazon. Stp automatically shut down the redundant links which creates the loops. 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. By default, the bridge priority value is set to 32768 in all cisco switches. Instructor spanning tree protocol is used ona local area network because in most casesswitches have redundant links for fault tolerance.
In this spanning tree protocol tutorial, i will present in simplest terms the operation of stp and indicate how this protocol prevents the creation of bridging loops. Understanding spanning tree protocol this section describes how spanningtree features work. Just like every coin has two sides, a redundant link, along with several advantages, has some disadvantages. Ccna network simulator ccna exam simulator ccent network simulator ccent exam simulator juniper simulator 18 stp points to remember 1. Configuring pervlan spanning tree protocol free ccna workbook. In this type of spanning tree protocol grouping of all vlans created for each single group. The spanning tree protocol stp allows redundant links in a network to prevent complete network failure if an active link fails, without the danger of layer 2 switching loops. But redundant links may also introduce physical switching loops that are undesirable. One big disadvantage of stp is the low convergence which is very important in switched network.
This is because layer 2 ethernet frameshave no time to live or time out mechanismbuilt into the frame. This standardized solution is called spanning tree protocol stp. The spanning tree protocol requires network devices to exchange messages to detect bridging loops. Lesson 79 introduction to cisco ipsec vpn technologies.
Spanning tree protocol stp is enabled, every switch in the network starts in the blocking state and later changes to the listening and learning states. Cisco spanning tree protocol guide stp examples and. Here you can find all materials needed to study for your ccna exam. Root port is the port that is closest to the root bridge, which means it is the port that receiving the lowestcost bpdu from the root every nonroot bridge must have a root port. It is also used to analyze the port speed in the topology and determine which port should be open and which port should be closed in order to provide a loopfree network. Spanning tree is effectively disabled in the network. Links that will cause a loop are put into a blocking state.
Jul, 2019 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. The election decides which switch will become the root bridge, as well as the. This section describes how spanning tree features work. With stp in place, you can have redundant links between switches in order to provide redundancy. This site developed to provide ccna tutorials material with no any cost. May 28, 2008 this document descibes spanning tree protocol stp in a wireless environment. What is the byte order used for transmitting datagram headers in the tcpip protocol suite. On each switch, display the spanning tree table with the show spanningtree command. Spanning tree protocol maintains a loopfree networkby pruning redundant links and monitors the stateof the network and will change the pathwaysto fit the current link conditions in orderto keep it operational. How is the ttl field used to prevent indefinite looping of ip datagrams. 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. Stp is enabled by default on all cisco switches, for all vlans.
The convergence time for legacy spanning tree protocol stp ieee 802. Cisco introduced several enhancements to the standard stp operation that were later incorporated in rapid spanning tree protocol rstp defined as ieee 802. If you are not sure how stp and rstp work, please read my stp tutorial and rstp tutorial. When you connect two or more layer 2 devices, an election is run to designate the root bridge. Stp or spanning tree protocol is a protocol used on switches that prevents layer 2 switching loops and layer 2 broadcast storms. Stp blocks some ports on switches with redundant links to prevent broadcast storms and ensure loopfree topology. This section describes how spanningtree features work. Rapid spanning tree protocol rstp, which significantly reduces the convergence time after a. Spanningtree protocol, or stp, prevents switching loops in the layer 2 portion of our network. As the name implies, stp, spans all switches in a network or subnet.
A computer network can be described as a system of interconnected devices that can communicate using some common standards called protocols. A redundant link is an additional link between two switches. Spanning tree protocol stp tutorial premium tutorial to provide for fault tolerance, many networks implement redundant paths between devices using multiple switches. This tutorial explains what the stp protocol is and how it removes. Stp will identify if there are any loops, and then disable or block. The root path cost is used to elect root port and we will discuss in the next part. Cisco network troubleshooting spanning tree lab 01.
This version is called pvst per vlan spanningtree and its the default on cisco switches. Configuring pervlan spanning tree protocol free ccna. Mst is the cisco implementation of mstp, an ieee standard protocol that provides up to 16 instances of rstp. Before we learn further about stp, we need to understand some of the common terms associated with it. A blocking port will not forward frames or learn mac addresses.
Spanning tree protocol stp ensures a loopfree topology in a local area network lan made up of switches. The development team have a good experience of networking. All working interfaces on the root bridge are placed in forwarding state. The following table lists some of the differences among the. Lesson 80 how to configure sitetosite ipsec vpn using ikev1 main mode. Lan switching configuration guide spanning tree protocol. The function of spanning tree protocol stp is to prevent layer 2 switching loop and broadcast storms in a local area network lan. Root selection varies depending on the bid of each switch in your lab resulting in. Ccna training rapid spanning tree protocol rstp tutorial. Ccna training spanning tree protocol stp tutorial 9tut. Consider, city network as a huge graph and now plans to deploy telephone lines in such a.