What is the purpose of the Spanning Tree Protocol (STP)?

A．To prevent routing loops

B．To create a default route

C．To provide multiple gateways for hosts

D．To maintain a loop-free Layer 2 network topology

E．To enhance the functions of SNMP

[单选题]In which Spanning-Tree states does a switch port learn MAC addresses? (Select two)A．BlockingB．ListeningC．ForwardingD．LearningE．Relaying

[单选题]命令“spanning-tree vlan”的功能是()。A．Catalyst3500系统下启用STPB．Catalyst6500系统下启用STPC．Catalyst3500系统下配置生成树优先级D．上述说法都

[单选题]命令“spanning£­tree vlan”的功能是______。A.Catalyst 3500系统下启用STPB.Catalyst 6500系命令“spanning-tree vlan＜vlan＞”的功能是______。A．Catalyst 3500系统下启用STPB．Catalyst 6500系统下启用STPC．Catalyst 3500系统下配置生成树优先级D．上述说法都不对

[单选题]What is the purpose of the text?A．To describe the job of a ROM．B．To provide information about ALRL．C．To announce an open position at ALRL．D．To make known the opening of the new laboratories．

[单选题]命令“spanning-tree vlan<vlan>”的功能是( )。A．) Catalyst 3500系统下配置生成树优先级B．) Catalyst 6500系统下启用STPC．) Catalyst 3500系统下启用STPD．)上述说法都不对

[单选题]What is NOT the purpose of this music program？A．To study the language of music.B．To learn more about the music.C．To give a complete background to the music.D．To give people some music to listen to.

[单选题]What is the main purpose of the passage?A． To teach patients ways for quick recovery.B． To present a report on a scientific research.C． To show the importance of a good lifestyle.D．, To give information about a kind of medicine.

[单选题]What is the main purpose of the passage?A．To show us the hidden beauty in our world.B．To warn us not to get lost in the fantasy wonderC．To argue against the misuse of the sense of wonderD．To discuss the influence of the world of make-believe

[单选题]What is the purpose of the intake/exhaust valves in a diesel engine? （）A . They regulate the combustion cycleB . They supply cooling waterC . They synchronize the ignition sparkD . They supply and regulate the lubricant flow

[单选题]What is the main purpose of the passage?A．To show us the hidden beauty in our world.B．to warn us not to get lost in the fantasy world.C．To argue against the misuse of the sense of wonder.D．To discuss the influence of the world of make-believe.