One of the main resposibilities of ICMP is to report(71). Although technology ha..

2011年下半年上午试卷综合知识

第 71 题


知识点	ICMP route
章/节	专业英语

One of the main resposibilities of ICMP is to report(71). Although technology has produced increasingly relaible transmission media, errors still exist and must be handled. IP is an(72)protocol. This means that error checking and error control are not a concern of IP. ICMP was designed, in part, to compensate for this shortcoming. Howerver, ICMP does not(73)errors, it simply report them. Error correction is left to the higher-level potocols. Error messages are always sent to the original(74)because the only information available in the datagram about the route is the source and destination IP addresses. ICMP use the source IP address to sent the error massage to the source of the(75).

A. numbers

B. functions

C. strings

D. errors

相关试题专业英语

第74题

2010年上半年

Both bus and tree topologies are characterized by the use of multipoint(71).For the bus, all stations attach, through appropriate hardware(72)known as..

第72题

2010年下半年

A transport layer protocol has several responsibilities. One is to create a process-to-process (program-to-program) communication; TCP uses port(71)to..

第71题

2019年上半年

Simple Network Management Protocol（SNMP）is an Internet Standard protocol for collecting and organizing information about managed devices on IP netwo..

知识点讲解

· ICMP

· route

ICMP

ICMP与IP位于同一层，它被用来传送IP的控制信息，它主要用来提供有关通向目的地址的路径信息。ICMP的Redirect信息通知主机通向其他系统的更准确的路径，而Unreachable信息则指出路径有问题。另外，如果路径不可用了，则ICMP可以使TCP连接终止。PING是最常用的基于ICMP的服务。

route

route命令的功能是显示和修改本地的IP路由表。如果不带参数，则给出帮助信息。

1）语法格式

2）参数说明

.-f：删除路由表中的网络路由、本地环路路由和组播路由。

.-p：与add命令联合使用时，一条路由被添加到注册表中，当TCP/IP启动时，用于初始化路由；与print命令联合使用时，则显示持久路由列表；对于其他命令，这个参数被忽略。

.Command：表示要运行的命令，可用的命令有add（添加路由）、change（修改已有的路由）、delete（删除路由）和print（打印路由）。

.Destination：说明目标地址，可以是网络地址、主机地址或默认路由。

.mask Netmask：说明目标地址对应的子网掩码。

.Gateway：说明下一跃点的IP地址。

.metric Metric：说明路由度量值，通常选择度量值最小的路由。

.if Interface：说明接口的索引。

更多复习资料
请登录电脑版软考在线 www.rkpass.cn

京B2-20210865 | 京ICP备2020040059号-5