Stp or spanning tree protocol is a protocol used on switches that prevents layer 2 switching loops and layer 2 broadcast storms. This is because layer 2 ethernet frameshave no time to live or time out mechanismbuilt into the frame. Ccna training spanning tree protocol stp tutorial free download as pdf file. The spanning tree protocol requires network devices to exchange messages to detect bridging loops. 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. Spanningtree protocol, or stp, prevents switching loops in the layer 2 portion of our network. By default, the bridge priority value is set to 32768 in all cisco switches. 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. Ccnp switch chapter 4 exam answers version 7 score 100%. 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. Rstp significantly reduces topology reconverging time after a.
Stp will identify if there are any loops, and then disable or block. 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. This tutorial explains what the stp protocol is and how it removes. Just like every coin has two sides, a redundant link, along with several advantages, has some disadvantages. 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. This standardized solution is called spanning tree protocol stp. 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. Stp spanning tree protocol step by step configuration. The main purpose of stp is to ensure that you do not create loops when you have redundant paths in your network. Here is an example network consisting of two computers connected together. This is very necessary in large networks that are designed to have redundancy like backup switches and multiple paths across the network. For an ethernet network to function properly, only one active. The message that a switch sends, allowing the formation of a loop free logical topology, is called a bridge protocol data unit bpdu.
Stp blocks some ports on switches with redundant links to prevent broadcast storms and ensure loopfree topology. Spanning tree protocol stp was developed to prevent the broadcast storms caused by. This webcast shows you the stp topics for which youre responsible on the ccna. Cisco developed, implemented and published the per vlan spanning tree pvst proprietary protocol using its own proprietary inter switch. A network reference model serves as a blueprint, detailing standards for how protocol communication should occur. To overcome this problem, in 2001, the ieee with document 802. This version is called pvst per vlan spanningtree and its the default on cisco switches.
How is the ttl field used to prevent indefinite looping of ip datagrams. Spanning tree protocol stp is a big topic on the ccna exam. The spanning tree protocol stp is layer 2 protocol. Spanning tree protocol stp for ccna rs 200125 and icnd2 200105 candidates duration. Stp overview stp is a layer 2 link management protocol that prov ides path redundancy while preventing loops in the network.
Rapid spanning tree protocol rstp, which significantly reduces the convergence time after a. 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. The election decides which switch will become the root bridge, as well as the. One of the topics on the ccna rs version 3 exam is spanning tree protocol stp. There are many pdf books also available some of them are paid. Free cisco certified network associate routing and switching ccna routing and switching online tutorials and study guides. But redundant links may also introduce physical switching loops that are undesirable. So therefore, if there is a tie in our value with spanningtree protocol, there has to be a tiebreaker mechanism. Types of spanning tree protocol stp explained ccna. Ccna tutorials are available to pass the ccna exam. Spanning tree is basically used to find a minimum path to connect all nodes in a graph. Switches running stp will build a map or topology of the entire switching network. To finds a redundant link, it uses an algorithm, known as the sta spanningtree algorithm.
With stp in place, you can have redundant links between switches in order to provide redundancy. 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. Ccna training rapid spanning tree protocol rstp tutorial. This document descibes spanning tree protocol stp in a wireless environment. 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 is a link management protocol that provides path redundancy while preventing undesirable loops in the network. On each switch, display the spanning tree table with the show spanningtree command. The root path cost is used to elect root port and we will discuss in the next part.
Lesson 79 introduction to cisco ipsec vpn technologies. 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. Understanding spanning tree protocol this section describes how spanningtree features work. If you have not yet registered, you will be prompted to register, before proceeding to access this content. Cisco introduced several enhancements to the standard stp operation that were later incorporated in rapid spanning tree protocol rstp defined as ieee 802. When the network is converging on a topology change, no traffic is forwarded to or from any of the network bridges and switches. Stp is enabled by default on all cisco switches, for all vlans. Lesson 80 how to configure sitetosite ipsec vpn using ikev1 main mode. Vlan0005 spanning tree enabled protocol ieee root id priority 32773 address 00. Spanning tree protocol stp is a network protocol designed to prevent layer 2 loops.
Ccna network simulator ccna exam simulator ccent network simulator ccent exam simulator juniper simulator 18 stp points to remember 1. 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. No particular configuration is needed to attain this. Understanding and configuring spanning tree protocol stp. Consider, city network as a huge graph and now plans to deploy telephone lines in such a. It is desirable to have redundant links in a switched lan so that a single link failure cannot interrupt normal operation of the network. The convergence time for legacy spanning tree protocol stp ieee 802. Root selection varies depending on the bid of each switch in your lab resulting in.
Ccna tutorials are available to pass the ccna exam 200125, icnd1 and icnd2. Configuring pervlan spanning tree protocol free ccna. 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. The problem is that when we create redundancyat a layer 2 level of our networks,we create loops that traffic will traverse indefinitely. What is the byte order used for transmitting datagram headers in the tcpip protocol suite. The transmitting switch port id, will be discussed later 2. As the name implies, stp, spans all switches in a network or subnet. This site developed to provide ccna tutorials material with no any cost. Before we learn further about stp, we need to understand some of the common terms associated with it. 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. Free cisco certified network associate ccna online. Ccna training spanning tree protocol stp tutorial network. All working interfaces on the root bridge are placed in forwarding state.
Free cisco certified network associate ccna online tutorials and study guides. A redundant link is an additional link between two switches. Another version of spanningtree is able to calculate a topology for each vlan. The golden rule of spanningtree protocol is lower is better.
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. Spanning tree protocol stp tutorial premium tutorial to provide for fault tolerance, many networks implement redundant paths between devices using multiple switches. Ccna tutorials are available on various websites and offline books. Spanning tree protocol stp is standardized as ieee 802. 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. Spanning tree protocol stp was developed before switches were created in order. Cisco network troubleshooting spanning tree lab 01. Cisco networking allinone for dummies add to cart amazon. Spanning tree protocol explained step by step youtube. Lan switching configuration guide spanning tree protocol. Spanning tree protocol stp finds the redundant link by the spanning tree algorithm.
To enable spanning tree, connect to your switch and type spanningtree mode while in global configuration mode. 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. The following figure shows a basic network with simplified 4digit mac. Protocols are covered in great detail in other guides. May 28, 2008 this document descibes spanning tree protocol stp in a wireless environment. Spanning tree protocol, or stp, prevents switching loops in the layer 2 portion of our network. Ccna training spanning tree protocol stp tutorial 9tut. The redundant link creates a loop between switches. Stp spanning tree protocol automatically removes layer 2 switching loops by shutting down the redundant links.
This webcast shows you the stp topics for which youre responsible on the ccna rs 200125 or icnd2 200105. This content is only accessible by registered users. Spanning tree protocol stp spanning tree protocol stp was developed to prevent the broadcast storms caused by switching loops. Spanning tree protocol stp for ccna rs 200125 and icnd2. Nov 16, 2016 one of the topics on the ccna rs version 3 exam is spanning tree protocol stp. 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. The development team have a good experience of networking. The spanning tree admin march 2, 2019 march 2, 2019 no comments on cisco rstp tutorial pdf. What is spanning tree protocol stp lesson 102 what is bridge protocol data unit bpdu frame. The following table lists some of the differences among the. A blocking port will not forward frames or learn mac addresses. Rapid spanning tree protocol rstp, which significantly reduces the convergence time after a topology change occurs in the network. How stp works video by sikandar shaik dual ccie rs.
You should have deep knowledge in basic networking, tcpip and ipv6 before start learning ccna routing and switching. It vigilantly monitors the network to find all links, making sure that no loops occur by blocking any redundant ones. Here you can find all materials needed to study for your ccna exam. While most people like the effects of redundancy, the redundancy can cause problems at layer 2. Stp is a layer 2 link management protocol that provides path redundancy while preventing loops in the network. Spanning tree protocol stp ensures a loopfree topology in a local area network lan made up of switches. 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. This lesson explains what is rapid spanning tree protocol rstp tutorials and cisco enhanced the original spanning tree protocol stp ieee d.
However, providing redundant paths between segments causes packets to be. Spanning tree protocol stp is a layer 2 protocol that runs on bridges and switches. This section describes how spanning tree features work. 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. Lesson 78 how to configure cisco ios zone based firewall.
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. In this type of spanning tree protocol grouping of all vlans created for each single group. Many people struggle with stp so in this video, we try to break it down as much as possible. Spanning tree protocol stp is a layer 2 network protocol used to prevent looping within a network topology. 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. Here you can find all materials needed to study for your ccna. Spanning tree protocol this document descibes spanning tree protocol stp in a wireless environment. Spanning tree protocol ccnax 200120 ccna practice tests. Mar 02, 2019 cisco developed, implemented and published the per vlan spanning tree pvst proprietary protocol using its own proprietary inter switch. We will focus on spanning tree protocol stp configuration and verification commands in this tutorial, as implemented on cisco switches. 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. Introduction to spanningtree spanningtree is a protocol that runs on our switches that helps us to solve loops.
Configuring pervlan spanning tree protocol free ccna workbook. Stp automatically shut down the redundant links which creates the loops. With the advent of layer 3 switching in lan environments, bridging now competes. Network reference models were developed to allow products from different manufacturers to interoperate on a network. Stp is on by default, but it only really comes alive when we have two or more switches interconnected with each other. Here you will find answers to spanning tree protocol questions. Ccna tutorials a perfect guide to getting ccna certified. Cisco spanning tree protocol guide stp examples and. A redundant link is usually created for backup purposes.
Spanningtree protocol is a link management protocol that provides path redundancy while preventing undesirable loops in the network. In modern networks this spanning tree protocol stp convergence time gap is not acceptable and cisco enhanced the. 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. One big disadvantage of stp is the low convergence which is very important in switched network. For a layer 2 network to function properly, only one active path can exist between any two stations. Lesson 76 c3pl cisco common classification policy language, class map, policy map and service policy. 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. Cisco ccna spanning tree protocol tutorial jared heinrichs. Instructor spanning tree protocol is used ona local area network because in most casesswitches have redundant links for fault tolerance. When you connect two or more layer 2 devices, an election is run to designate the root bridge.
Stp is a layer 2 protocol that runs on switches and bridges, the purpose of stp is to remove switching loops. The switch with the lowest switch id will become the root bridge. Cisco ccna spanning tree protocol tutorial in most networks larger than your typical smb switched networks, there will be path redundancy. This section describes how spanningtree features work. Infrastructure devices might also learn endstation mac addresses on multiple layer 2 interfaces. A computer network can be described as a system of interconnected devices that can communicate using some common standards called protocols. These looping frames would cause network performance problems.
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