STP Lab 31 32Word文档下载推荐.docx

1、Connect to DLS1 and enter the following commands:SwitchenableSwitch#configure terminalSwitch（config）#hostname DLS1DLS1（config）#enable secret classDLS1（config）#line console 0DLS1（config-line）#password ciscoDLS1（config-line）#loginConnect to DLS2 and enter the following commands:2 - 6 CCNP: Building Mu

2、ltilayer Switched Networks v5.0 - Lab 3-1 Copyright 2006, Cisco Systems, IncSwitch（config）#hostname DLS2DLS2（config）#enable secret classDLS2（config）#line console 0DLS2（config-line）#password ciscoDLS2（config-line）#loginConnect to ALS1 and enter the following commands:Switch（config）#hostname ALS1ALS1（

3、config）#enable secret classALS1（config）#line console 0ALS1（config-line）#password ciscoALS1（config-line）#loginConnect to ALS2 and enter the following commands:Switch# configure terminalSwitch（config）#hostname ALS2ALS2（config）#enable secret classALS2（config）#line console 0ALS2（config-line）#password ci

4、scoALS2（config-line）#loginStep 2After the cables are connected and the switch detects the redundant links,spanning tree is initiated.By default, spanning tree runs on every port. When a new link becomes active,the port goes through the listening, learning, and forwarding states before itbecomes acti

5、ve. During this period, the switch discovers if it is connected toanother switch or an end-user device.If another switch is detected, the two switches begin creating a spanning tree.One of the switches is elected as the root of the tree. Then an agreement isestablished as to which links to keep acti

6、ve and which links to disable if multiplelinks exist.1. What type of frame does STP use to communicate with other switches?Note The results in this lab will vary. Spanning tree operation is basedon the MAC address of the switches.Observe the LEDs on the switch to check the status of the link. A brig

7、ht greenlight indicates an active link. An amber light indicates an inactive link.3 - 6 CCNP:Step 3Verify STP with the show spanning-tree command on DLS1:DLS1#show spanning-treeVLAN0001Spanning tree enabled protocol ieeeRoot ID Priority 32769Address 000a.b8a9.d680Cost 19Port 13 （FastEthernet0/11）Hel

8、lo Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 32769 （priority 32768 sys-id-ext 1）Address 000a.b8a9.d780Aging Time 300Interface Role Sts Cost Prio.Nbr Type- - - - - -Fa0/7 Desg FWD 19 128.9 P2pFa0/8 Desg FWD 19 128.10 P2pFa0/9 Desg FWD 19 128.11 P2pFa0/10 Desg FWD 19 128.12 P2pF

9、a0/11 Root FWD 19 128.13 P2pFa0/12 Altn BLK 19 128.14 P2pVerify STP with the show spanning-tree command on DLS2:DLS2#show spanning-treeThis bridge is the rootFa0/11 Desg FWD 19 128.13 P2pFa0/12 Desg FWD 19 128.14 P2pVerify STP with the show spanning-tree command on ALS1:ALS1#show spanning-tree4 - 6

10、CCNP:Port 11 （FastEthernet0/9）Address 0019.0635.5780Interface Role Sts Cost1d22h: %SYS-5-CONFIG_I: Configured from console by console Prio.NbrTypeFa0/7 Altn BLK 19 128.9 P2pFa0/8 Altn BLK 19 128.10 P2pFa0/9 Root FWD 19 128.11 P2pFa0/10 Altn BLK 19 128.12 P2pVerify STP with the show spanning-tree com

11、mand on ALS2:ALS2#show spanning-treePort 9 （FastEthernet0/7）Address 0019.068d.6980Fa0/7 Root FWD 19 128.9 P2pFa0/9 Altn BLK 19 128.11 P2pFa0/11 Altn BLK 19 128.13 P2pNotice that between two switches, one of the two ports is set to blocking.Blocking could occur on the access layer switch or the distr

12、ibution layer switch. Ifall ports have their default setting, the higher interface number of the two ports isset to blocking.The switch port is in blocking state because it detected two links between thesame switches. This would result in a bridge loop if the switch logically disablesone link.5 - 6

13、CCNP:Note Your output may differ, because all switches have the defaultbridge priority of 32769 and selection of the root bridge is basedupon the lowest switch MAC address. The sample output belowmay also differ from those in your lab, because they weregenerated with a different set of switches.Afte

14、r reviewing the spanning tree output, answer the following questions.1. Which switch is the root of the spanning tree?2. How can the root switch be identified?3. Why was that switch selected as the root?6 - 6 CCNP:4. What caused one port to be in blocking state over another?5. What caused one link t

15、o be blocked over another?Step 4Create a diagram of the spanning tree topology for VLAN 01. With Cisco Catalystswitches, there is a different spanning tree state for each VLAN. Identify the rootbridge, root ports, and designated ports.In this lab, the default operation of spanning tree was observed.

16、 Since no bridgepriorities were specified, the switch with the lowest MAC address was elected asthe root. Since no link priorities were changed, the link with the lowest cost waschosen as the active link. If costs were equal, the tie was broken by the lowestport number.In a later lab, the default ST

17、P behavior will be modified so that spanning treeworks according to specifications.ChallengeTry to guess how your topology would look if you completely removed the rootswitch. Remember that the switch with the lowest MAC address becomes theroot.Now, shut down all the ports on your current root switc

18、h. Use the showspanning-tree command on the other switches. Did the topology converge theway you thought it would?1 - 12 CCNP: Building Multilayer Switched Networks v5.0 - Lab 3-2 Copyright Lab 3-2 Modifying Default Spanning Tree BehaviorThe purpose of this lab is to observe what happens when the de

19、fault spanningtree behavior is modified.links. In this lab, you will see what happens when the default spanning treebehavior is modified.Start by deleting vlan.dat, erasing the startup configuration, and reloading yourswitches. After reloading the switches, give them hostnames. You can finddetailed instructions in Lab 2.0.Us