Unix/Linux命令行小技巧（15）- 显示端口的状态及原因

使用“nmap --reason ip-address”命令可以显示当前IP地址上端口的状态及原因。
举个例子：

[root@localhost nan]# nmap --reason 192.168.23.150

Starting Nmap 6.46 ( http://nmap.org ) at 2015-01-13 15:17 CST
Nmap scan report for localhost.localdomain (192.168.23.150)
Host is up, received localhost-response (0.0000030s latency).
Not shown: 995 closed ports
Reason: 995 resets
PORT     STATE SERVICE REASON
22/tcp   open  ssh     syn-ack
23/tcp   open  telnet  syn-ack
111/tcp  open  rpcbind syn-ack
3306/tcp open  mysql   syn-ack
6699/tcp open  napster syn-ack

Nmap done: 1 IP address (1 host up) scanned in 0.09 seconds

技巧出处：https://twitter.com/nixcraft/status/272866836545163264。