ccna exam prep book

ccna exam prep book.Sl#show spanning-tree summaryView the summary information of STP Switch is in pvst mode Current STP operation mode Rootbridge for: VLAN0001 This switch is the root bridge of VLAN1 Extended system ID is enabled Extended system ID is enabled Portfast Default is disabled No global enable PortFast PortFast BPDU Guard Default is disabled No global enable BPDUGuard Port fast BPDU Filter Default is disabled// No BPDUFilter is enabled globallyLoopguard Default is disabled is not globally enabled EtherChannel misconfig guard is enabled is enabled UplinkFast is disabled is not enabled UplinkFast BackboneFast is disabled BackboneFast is not enabledConfigured Pathcost method used is short The configured overhead calculation method is short integer Name Blocking Listening Learning Forwarding STP ActiveVLAN0001 00 0 3 3 VLAN0002 10 0 2 32vlans 100 56 The above 6 lines show the number of STP port states in each VLAN and the summary numberFemale [Technology End ExtensionThe convergence time of STPdEEE 802.1d) usually takes 30~50 seconds. In addition to the PortFast feature, the STP convergence time can also be reduced by UplinkFast and BackboneFast technologies.1 UplinkFast is often used on the access layer switch to switch to the backup link immediately when the primary link on the core switch to which it is connected fails, without the need for 30 or 50 seconds to elapse. UplinkFast only needs to be configured on the access layer switch. The configuration command is spanning-treeuplinkfasto in global mode2 BackboneFast is primarily used between trunk switches, and can switch to the backup link in 20 seconds less than the original 50 seconds when a failure occurs on the link between the trunk switches. BackboneFast needs to be configured on all switches. The configuration command is spanning-tree backbonefasto in global mode14.4.2 Experiment 2: Configuring STP Protection