1、ping扫描：扫描192.168.0.0/24网段上有哪些主机是存活的；
　　[root@laolinux ~]# nmap -sP 192.168.0.0/24
　　Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2009-04-25 06:59 CST
　　Host laolinux (192.168.0.3) appears to be up.
　　Host 192.168.0.20 appears to be up.
　　MAC Address: 00:1E:4F:CD:C6:0E (Unknown)
　　Host 192.168.0.108 appears to be up.
　　MAC Address: 00:E3:74:27:05:B7 (Unknown)
　　Host 192.168.0.109 appears to be up.
　　MAC Address: 00:E0:E4:A6:14:6F (Fanuc Robotics North America)
　　Host 192.168.0.111 appears to be up.
　　MAC Address: 00:E0:E4:A6:1C:91 (Fanuc Robotics North America)
　　Host 192.168.0.114 appears to be up.
　　MAC Address: 00:11:1A:35:38:65 (Motorola BCS)
　　Host 192.168.0.118 appears to be up.
　　MAC Address: 00:E0:2A:51:AC:5B (Tandberg Television AS)
　　Host 192.168.0.119 appears to be up.
　　MAC Address: 00:EA:E5:C1:21:D6 (Unknown)
　　Host 192.168.0.124 appears to be up.
　　MAC Address: 00:E0:4C:39:05:81 (Realtek Semiconductor)
　　Host 192.168.0.127 appears to be up.
　　MAC Address: 00:11:1A:35:38:62 (Motorola BCS)
　　Host 192.168.0.128 appears to be up.
　　MAC Address: 00:E0:E4:A6:1C:96 (Fanuc Robotics North America)
　　Host 192.168.0.134 appears to be up.
　　MAC Address: 00:E0:2A:51:AC:5F (Tandberg Television AS)
　　Host 192.168.0.135 appears to be up.
　　MAC Address: 00:11:1A:35:38:60 (Motorola BCS)
　　Host 192.168.0.137 appears to be up.
　　MAC Address: 00:1F:06:D6:3E:BA (Unknown)
　　Host 192.168.0.139 appears to be up.
　　MAC Address: 00:E0:E4:A6:1C:92 (Fanuc Robotics North America)
　　Host 192.168.0.140 appears to be up.
　　MAC Address: 00:1F:1A:39:1B:8D (Unknown)
　　Host 192.168.0.155 appears to be up.
　　MAC Address: 00:1C:23:4C:DB:A0 (Unknown)
　　Host 192.168.0.211 appears to be up.
　　MAC Address: 00:1D:72:98:A2:8C (Unknown)
　　Host 192.168.0.220 appears to be up.
　　MAC Address: 00:40:45:20:8C:93 (Twinhead)
　　Host 192.168.0.221 appears to be up.
　　MAC Address: 00:09:6B:50:71:26 (IBM)
　　Nmap finished: 256 IP addresses (20 hosts up) scanned in 3.818 seconds
　　2、端口扫描：扫描192.168.0.3这台主机开放了哪些端口；
　　[root@laolinux ~]# nmap -sT 192.168.0.3
　　Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2009-04-25 07:02 CST
　　Interesting ports on laolinux (192.168.0.3):
　　Not shown: 1667 closed ports
　　PORT      STATE SERVICE
　　21/tcp    open  ftp
　　22/tcp    open  ssh
　　25/tcp    open  smtp
　　53/tcp    open  domain
　　80/tcp    open  http
　　110/tcp   open  pop3
　　111/tcp   open  rpcbind
　　143/tcp   open  imap
　　964/tcp   open  unknown
　　993/tcp   open  imaps
　　995/tcp   open  pop3s
　　3306/tcp  open  mysql
　　10000/tcp open  snet-sensor-mgmt
　　Nmap finished: 1 IP address (1 host up) scanned in 4.755 seconds
　　3、隐藏扫描，只在目标主机上留下很少的日志信息：隐藏扫描192.168.0.220
　　[root@laolinux ~]# nmap -sS 192.168.0.127
　　Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2009-04-25 07:08 CST
　　Interesting ports on 192.168.0.127:
　　Not shown: 1675 closed ports
　　PORT    STATE SERVICE
　　21/tcp  open  ftp
　　135/tcp open  msrpc
　　139/tcp open  netbios-ssn
　　445/tcp open  microsoft-ds
　　912/tcp open  unknown
　　MAC Address: 00:11:1A:35:38:62 (Motorola BCS)
　　Nmap finished: 1 IP address (1 host up) scanned in 3.121 seconds
　　4、UDP端口扫描：扫描192.168.0.127开放了哪些UDP端口；
　　[root@laolinux ~]# nmap -sU 192.168.0.127
　　Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2009-04-25 07:08 CST
　　Interesting ports on 192.168.0.127:
　　Not shown: 1480 closed ports
　　PORT     STATE         SERVICE
　　123/udp  open|filtered ntp
　　137/udp  open|filtered netbios-ns
　　138/udp  open|filtered netbios-dgm
　　445/udp  open|filtered microsoft-ds
　　500/udp  open|filtered isakmp
　　1900/udp open|filtered UPnP
　　4500/udp open|filtered sae-urn
　　MAC Address: 00:11:1A:35:38:62 (Motorola BCS)
　　Nmap finished: 1 IP address (1 host up) scanned in 2.947 seconds
　　5、操作系统识别：
　　[root@laolinux ~]# nmap -sS -O  192.168.0.127
　　Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2009-04-25 07:09 CST
　　Interesting ports on 192.168.0.127:
　　Not shown: 1675 closed ports
　　PORT    STATE SERVICE
　　21/tcp  open  ftp
　　135/tcp open  msrpc
　　139/tcp open  netbios-ssn
　　445/tcp open  microsoft-ds
　　912/tcp open  unknown
　　MAC Address: 00:11:1A:35:38:62 (Motorola BCS)
　　Device type: general purpose
　　Running: Microsoft Windows 2003/.NET|NT/2K/XP
　　OS details: Microsoft Windows 2003 Server or XP SP2
　　Nmap finished: 1 IP address (1 host up) scanned in 5.687 seconds