[root@chenyi~]# nmap -p 21 192.168.1.0/24 # -p 选项，指定目标端口
Starting Nmap5.51(http://nmap.org ) at 2012-12-06 09:29 CST
Nmap scan report for192.168.1.1
Host isup(0.0035slatency).
PORT STATE SERVICE
21/tcp filtered ftp#状态未知，可能被过滤
MAC Address:00:1F:8F:69:27:53(Shanghai Bellmann Digital Source Co.)
Nmap scan report for192.168.1.103
Host isup(0.00099slatency).
PORT STATE SERVICE
21/tcp closed ftp
MAC Address:20:7C:8F:6B:E6:3E(Quanta Microsystems)
Nmap scan report for192.168.1.108
Host isup(0.0021slatency).
PORT STATE SERVICE
21/tcp closed ftp
MAC Address:88:AE:1D:26:0B:0B(Compal Information(kunshan)co.)
Nmap scan report for192.168.1.110
Host isup(0.000093slatency).
PORT STATE SERVICE
21/tcp closed ftp
Nmap scan report for192.168.1.210
Host isup(0.0091slatency).
PORT STATE SERVICE
21/tcp filtered ftp
MAC Address:00:0C:29:CC:F3:02(VMware)
Nmap scan report for192.168.1.253
Host isup(0.0020slatency).
PORT STATE SERVICE
21/tcp filtered ftp
MAC Address:14:CF:92:47:07:04(Unknown)
Nmap done:256IP addresses(6hosts up)scanned in43.93s<strong>econds</strong>
