1. 实验结果
　　$ (master)$ nmap xx.xx.xx.xx
　　Starting Nmap 5.51 ( http://nmap.org ) at 2016-04-24 19:19 PDT
　　Nmap scan report for slc09wqk.us.oracle.com (10.245.251.161)
　　Host is up (0.00069s latency).
　　Not shown: 993 closed ports
　　PORT     STATE SERVICE
　　22/tcp   open  ssh
　　111/tcp  open  rpcbind
　　513/tcp  open  login
　　514/tcp  open  shell
　　2049/tcp open  nfs
　　3306/tcp open  mysql
　　5989/tcp open  wbem-https
　　Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds
　　2. 总结：
　　（1）端口号的概念：用来标定应用层的程序。数据经过传输层之后，通过端口号找到应用层。
　　（2）nmap的返回结果：列出目标ip上的开放端口和各个端口上运行的应用层服务协议。
　　（3）应用层协议介绍：
　　A. rpcbind：NFS服务依赖于它
　　B. wbem-https（基于web的企业管理）：网络管理协议。
　　Web Based Enterprise Management is an Industry initiative to provide management of systems， networks， users and applications across multiple vendor environments. WBEM simplifies system management， providing better access to both software and hardware data that is readable by WBEM compliant applications.
　　WBEM has been designed to be compatible with all the major existing management protocols， including SNMP， DMI， and CMIP. WBEM is a DMTF standard.