An utility to test the availability of Internet Application.
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Just like ‘ping’ to test the IP layer availability, a small program should be designed,
developed, to test the availability of Internet Applications like, WWW/FTP/TFTP/DNS/DHCP/SNMP.
The utility could be in a CLI or GUI user interface.
The input is the FQDN or IP address of the target computer for testing.
The output of the utility shall contain the following
- The name of your program
- The date/time your program started
- The availability of the Internet Application services
- The time used to get the service, just like a ‘ping’, such as www-ping, ftp-ping, dhcp-ping, …

Example:
c:\>dhcp-ping 202.126.3.16
DHCP-PING (ver.1.2) is an utility to test the availability of DHCP service.
The current date/time: 2006/11/06 10:22:54
DHCP service is available from server [202.126.3.16].
The response time is 305ms.
c:\>

原题就是这样了，哪位蝈蝈能帮忙看一下，谢谢了

先把你选的服务的协议分析一下，看看客户端和服务端的对应端口以及应答信息，然后根据这些来写。
客户端向服务端发送请求，同时启动一个计时器等待服务端应答数据，然后分析服务端返回的数据，如果接受连接就说明有这个服务，再加上程序名、时间之类的信息就行了。
为了防止网络偶尔出错，最好多发几个请求，只要有一个成功就可以认为服务存在，时间就取成功应答的平均值。
相当于一个port scanner，不过要简单的多，因为只要分析一类端口。


[ 此贴被ufly在2007-01-12 21:58重新编辑 ]