说明：  1、根据主机的IP地址，获取主机的物理地址的程序。 2．根据Internet的域名地址获取主机的IP地址的实验程序。 3. 根据主机名获取主机的IP地址。
(1, according to the IP addresses, access the mainframe physical address procedures. 2. According to Internet domain addresses access to the host's IP address experimental procedure. 3. According to mainframe host name to obtain the IP address.)