以下哪些接口可以做为R2501的serial0的备份接口？（）

A:serial1 B:serial2 C:console口 D:X.25的一条虚电路

根据以下的配置，请判断当主接口serial0出故障后，哪一个备份接口最先被启用。（）
Quidway（config-if-Serial0）#backup interfaceserial130
Quidway（config-if-Serial0）#backup interfaceserial240
Quidway（config-if-Serial0）#backup logic-channel350
Quidway（config-if-Serial0）#backup logic-channel235

A:serial1 B:serial2 C:logic-channel2 D:logic-channel3

可以通过哪些命令查看接口Serial1/0/1的配置信息（）.

A:[Quidway]display current-configuration B:[Quidway-Serial1/0/1]display this C:[Quidway]view saved-configuration D:[Quidway]show current-configuration

两台空配置的MSR路由器RTA、RTB通过各自的Serial1/0接口背靠背互连。在两台路由器上做如下配置：RTA：[RouterA-Serial1/0]link-protocolfrietf[RouterA-Serial1/0]ipaddress10.1.1.130[RouterA-Seria11/0]frmapip10.1.1.230RTB：[RouterB-Serial1/0]link-protocolfrietf[RouterB-Serial1/0]interfaceserial0/0.1[RouterB-Serial1/0.1]ipaddress10.1.1.230[RouterB-Serial1/0.1]frmapip10.1.1.130路由器之间的物理链路良好，那么下面说法正确的是（）。

A:两台路由器上都没有配置DLCI，在RTA上不能ping通RTB B:在RTA上不能ping通10.1.1.2 C:在RTA上可以ping通10.1.1.2 D:在上述配置中，如果仅将RTB上子接口serial0/0.1的类型改为P2MP，那么在RTA上不能ping通10.1.1.2 E:在上述配置中，如果仅将RTB上子接口serial0/0.1的类型改为P2MP，那么在RTA上可以ping通10.1.1.2

某路由器通过Serial1/0接口连接运营商网络，要在此路由器上配置默认路由从而实现访问Internet的目的，如下哪些配置一定是正确而且有效的？（）

A:iproute-static0.0.0.00Serial1/0 B:iproute-static0.0.0.00.0.0.0Serial1/0 C:iproute-static255.255.255.2550.0.0.0Serial1/0 D:以上配置都不正确

Traditional Internet access methods like dial-up were so slow that host computers were connected to the dial-up. (6) at the customer premise over slow (7) ports. PPP was designed to run directly over these serial links. But with the advent of broadband Internet (8) technologies such as ADSL and cable modems there has been a considerable increase in the bandwidth delivered to the end users. This means that the host computers at the customer premise connect to the (9) or cable "modem" over a much faster medium such as Ethernet. It also means that multiple (10) can connect to the Internet through the same connection.

A:parallel B:digital C:serial D:variable

在图8-9所示的反向Telnet网络拓扑图中，路由器Router的异步串行接口Serial1/0对应的绝对线路号为33，与Line33连接的MODEMA对应的端口号为2033。使用（）命令可以反向Telnet到MODEMA上对其进行配置。

A:telnet 10.0.0.1 2033 B:telnet Serial 1/0 2033 C:telnet 2033 Serial 1/0 D:telnet 10.0.0.1 Loopback0

在某路由器上已经配置了一个访问控制列表1，并且使用了防火墙功能。现在需要对所有通过Serial0接口进入的数据包使用规则1进行过滤。如下可以达到要求的是 (53) 。

A:在Serial0的接口模式配置：ip access-group 1 out B:在全局模式配置：access-group 1 serial0 out C:在Serial0的接口模式配置：access-group 1 in D:在Serial0的接口模式配置：ip access-group 1 in

在图8-9所示的反向Telnet网络拓扑图中，路由器Router的异步串行接口Serial1/0对应的绝对线路号为33，与Line33连接的MODEMA对应的端口号为2033。使用（）命令可以反向Telnet到MODEMA上对其进行配置。

A:telnet 10.0.0.1 2033 B:telnet Serial 1/0 2033 C:telnet 2033 Serial 1/0 D:telnet 10.0.0.1 Loopback0

Traditional Internet access methods like dial-up were so slow that host computers were connected to the dial-up （71） at the customer premise over slow （72） ports. PPP was designed to run directly over these serial links. But with the advent of broadband Internet （73）technologies such as ADSL and cable modems there has been a considerable increase in the bandwidth delivered to the end users. This means that the host computers at the customer premise connect to the （74） or cable "modem" over a much faster medium such as Ethernet.It also means that multiple （75） can connect to the Internet through the same connection.

A:parallel B:digital C:serial D:variable