CMS专题
单选题What is the importance of using Virtual Output Queues on ingress Line Cards in a high-end router？（）A Prevents head-of-line blockingB Uses less memoryC Increases forwarding performanceD Simplifies configuration
题目
Prevents head-of-line blocking
Uses less memory
Increases forwarding performance
Simplifies configuration
相似问题和答案
第1题：
A. Provides fast convergence times.
B. Supports connections of multiple backbones.
C. Eliminates the need for a Designated Router.
D. Supports non direct connections to the backbone.
第2题：
A. InterSwitch Link
B. Virtua LAN
C. Virtual Output Queuing
D. virtual storage area network
第3题：
有如下程序： #include＜iostream＞ using namespace std； class Base{ public： void output( ){cout＜＜l；} virtual void Print( ){cout＜＜'B'；} }； class Derived：public Base{ public： void output( ){cout＜＜1；} void Print( ){cout＜＜'D'；} }； int main( ){ Base*prt=new Derived； prt-＞output( )； prt-＞Print( )； delete prt； return 0； } 程序的输出结果是
A．1B
B．1D
C．2B
D．2D
解析：基类指针可以指向派生类对象，但是只能访问从基类中继承来的成员。派生类对从基类继承来的成员可以被重新定义。故打印1D
第4题：
What are the differences between LLQ and CBWFQ？（）
- A、LLQ supports the addition of strict priority queuing
- B、With LLQ， bandwidth allocations for the priority queue and all the CBWFQ queues areconfigured using the priority command
- C、LLQ is configured using MQC and CBWFQ is configured using the fair-queue command
- D、LLQ priority queue bandwidth is policed with a congestion aware policer
- E、LLQ does not support WFQ on the default traffic class （class-default）
正确答案:A,D
第5题：
What are two purposes of a forwarding class?（）
- A、to identify traffic that should be dropped
- B、to classify traffic
- C、to identify traffic that should receive common treatment
- D、to assign traffic to output queues
正确答案:C,D
第6题：
A. Administratively shut down the interface.
B. Physically secure the interface.
C. Create an access list and apply it to the virtual terminal interfaces with the access-group command.
D. Configure a virtual terminal password and login process.
E. Enter an access list and apply it to the virtual terminal interfaces using the access-class command.
第7题：
A. Administratively shut down the interface.
B. Physically secure the interface.
C. Create an access list and apply it to the virtual terminal interfaces with the access-group command.
D. Configure a virtual terminal password and login process.
E. Enter an access list and apply it to the virtual terminal interfaces using the access-class command.
第8题：
有如下程序： #inClude<iostream> using namespaCe std； Class Base{ publiC： void output{Cout<<1；} virtual void Print{Cout<<B’；} }； Class Derived：publiC Base{ publiC： void output{Cout<<2；} void Print{Cout<<’D ；} }； int main { Base * ptr=new Derived； ptr一>output； ptr一>Print； delete ptr； retum0； } 执行这个程序的输出结果是( )。
A.1B
B.lD
C.2B
D.2D
在某基类中声明为vitua1并在一个或多个派生类中被重新定义的成员函数，本题中定义了一个指向派生类对象的基类指针ptr，执行ptr一>outpnt后，会执行基类的output函数，输出1，由于Print是虚函数，所以ptr->Print会执行派生类的Print，即输出D，所以本题答案为B。
第9题：
On Cisco Nexus 5000 Series Switches， where are the virtual output queues implemented， and what is the main purpose of virtual output queues？（）
- A、 on all ingress interfaces； to ensure maximum throughput on a per-egress， per-CoS basis
- B、 on all ingress interfaces； to provide independent congestion management and 16 queues
- C、 on all egress interfaces； so that a congested egress port does not affect traffic directed to other egress ports
- D、 on all egress interfaces； to prevent head-of-line blocking by utilizing multiple virtual output queues
- E、 on all egress interfaces； to be able to use EEE 802.1p CoS
正确答案:A
第10题：
You are the Cisco Network Designer in Cisco.com. What is the term for a logical SAN which provides isolation among devices physically connected to the same fabric？（）
- A、 InterSwitch Link
- B、 Virtua LAN
- C、 Virtual Output Queuing
- D、 virtual storage area network
正确答案:D