● The defacto standard Application Program Interface （API） for TCP/IP applications is the “sockets” interface. Although this API was developed for __(1)__ in the early 1980s it has also been implemented on a wide variety of non-Unix systems。 TCP/IP __(2)__written using the sockets API have in the past enjoyed a high degree of portability and we would like the same __(3)__with IPv6 applications。 But changes are required to the sockets API to support IPv6 and this memo describes these changes。These include a new socket address structure to carry IPv6 __(4)__，new  address conversion functions，and some new socket options。These extensions are designed to provide access to the basic IPv6 features required by TCP and UDP applications，including multicasting， while introducing a minimum of change into the system and providing complete __(5)__for existing IPv4 applications。

（1）A．Windows  

B．Linux      

C．Unix       

D．DOS

（2）A．applications     

B．networks    

C．protocols  

D．systems

（3）A．portability

B．availability    

C．capability 

D．reliability

（4）A．connections    

B．protocols       

C．networks  

D．addresses

（5）A．availability

B．compatibility 

C．capability   

D．reliability

● PC机不能接入因特网，这时采用抓包工具捕获的以太网接口发出的信息如下：

可以看出该PC机的IP地址为___(6)__，默认网关IP地址为为__(7)__。PC不能接入Internet的原因可能是__(8)__。

（6）A．213.127.115.31 

B．213.127.115.255

C．213.127.115.254 

D．224.1.1.1

（7）A．213.127.115.31 

B．213.127.115.255

C．213.127.115.254 

D．224.1.1.1

（8）A．DNS解析错误 

B．TCP/IP协议安装错误

C．不能连接到网关

D．DHCP服务工作不正常

● IEEE802.11标准采用的工作频段是__(9)__，下列标准中采用双频工作模式的是__(10)__。 
IEEE802.11标准采用的工作频段是（），下列标准中采用双频工作模式的是（）。

（9）A．900MHz和800MHz 

B．900MHz和2.4GHz

C．5GHz和800MHz 

D．2.4GHz和5GHz

（10）A．IEEE802.11a

B．IEEE802.11b

C．IEEE802.11g

D．IEEE802.11n