nmap，也就是Network Mapper，是Linux下的网络扫描和嗅探工具包。

nmap是在网络安全渗透测试中经常会用到的强大的扫描器。功能之强大，不言而喻。下面介绍一下它的几种扫描命令。具体的还是得靠大家自己学习，因为实在太强大了。

nmap安装

yum install nmap

nmap场景命令参数

Usage: nmap [Scan Type(s)] [Options] {target specification}
TARGET SPECIFICATION:
Can pass hostnames, IP addresses, networks, etc.
Ex: scanme.nmap.org, microsoft.com/24, 192.168.0.1; 10.0.0-255.1-254
-iL <inputfilename>: Input from list of hosts/networks
-iR <num hosts>: Choose random targets
--exclude <host1[,host2][,host3],...>: Exclude hosts/networks
--excludefile <exclude_file>: Exclude list from file
HOST DISCOVERY:
-sL: List Scan - simply list targets to scan
-sn: Ping Scan - disable port scan
-Pn: Treat all hosts as online -- skip host discovery
-PS/PA/PU/PY[portlist]: TCP SYN/ACK, UDP or SCTP discovery to given ports
-PE/PP/PM: ICMP echo, timestamp, and netmask request discovery probes
-PO[protocol list]: IP Protocol Ping
-PR: ARP ping - does not need HW address -> IP translation
-n/-R: Never do DNS resolution/Always resolve [default: sometimes]
--dns-servers <serv1[,serv2],...>: Specify custom DNS servers
--system-dns: Use OS's DNS resolver
--traceroute: Trace hop path to each host
SCAN TECHNIQUES:
-sS/sT/sA/sW/sM: TCP SYN/Connect()/ACK/Window/Maimon scans
-sU: UDP Scan
-sN/sF/sX: TCP Null, FIN, and Xmas scans
--scanflags <flags>: Customize TCP scan flags
-sI <zombie host[:probeport]>: Idle scan
-sY/sZ: SCTP INIT/COOKIE-ECHO scans
-sO: IP protocol scan
-b <FTP relay host>: FTP bounce scan
PORT SPECIFICATION AND SCAN ORDER:
-p <port ranges>: Only scan specified ports
Ex: -p22; -p1-65535; -p U:53,111,137,T:21-25,80,139,8080,S:9
-F: Fast mode - Scan fewer ports than the default scan
-r: Scan ports consecutively - don't randomize
  --top-ports <number>: Scan <number> most common ports
  --port-ratio <ratio>: Scan ports more common than <ratio>
SERVICE/VERSION DETECTION:
  -sV: Probe open ports to determine service/version info
  -sR: Check what service uses opened ports using RPC scan
  --version-intensity <level>: Set from 0 (light) to 9 (try all probes)
  --version-light: Limit to most likely probes (intensity 2)
  --version-all: Try every single probe (intensity 9)
  --version-trace: Show detailed version scan activity (for debugging)
SCRIPT SCAN:
  -sC: equivalent to --script=default
  --script=<Lua scripts>: <Lua scripts> is a comma separated list of 
           directories, script-files or script-categories
  --script-args=<n1=v1,[n2=v2,...]>: provide arguments to scripts
  --script-trace: Show all data sent and received
  --script-updatedb: Update the script database.
OS DETECTION:
  -O: Enable OS detection
  --osscan-limit: Limit OS detection to promising targets
  --osscan-guess: Guess OS more aggressively
TIMING AND PERFORMANCE:
  Options which take <time> are in seconds, or append 'ms' (milliseconds),
  's' (seconds), 'm' (minutes), or 'h' (hours) to the value (e.g. 30m).
  -T<0-5>: Set timing template (higher is faster)
  --min-hostgroup/max-hostgroup <size>: Parallel host scan group sizes
  --min-parallelism/max-parallelism <numprobes>: Probe parallelization
  --min-rtt-timeout/max-rtt-timeout/initial-rtt-timeout <time>: Specifies
      probe round trip time.
  --max-retries <tries>: Caps number of port scan probe retransmissions.
  --host-timeout <time>: Give up on target after this long
  --scan-delay/--max-scan-delay <time>: Adjust delay between probes
  --min-rate <number>: Send packets no slower than <number> per second
  --max-rate <number>: Send packets no faster than <number> per second
FIREWALL/IDS EVASION AND SPOOFING:
  -f; --mtu <val>: fragment packets (optionally w/given MTU)
  -D <decoy1,decoy2[,ME],...>: Cloak a scan with decoys
  -S <IP_Address>: Spoof source address
  -e <iface>: Use specified interface
  -g/--source-port <portnum>: Use given port number
  --data-length <num>: Append random data to sent packets
  --ip-options <options>: Send packets with specified ip options
  --ttl <val>: Set IP time-to-live field
  --spoof-mac <mac address/prefix/vendor name>: Spoof your MAC address
  --badsum: Send packets with a bogus TCP/UDP/SCTP checksum
OUTPUT:
  -oN/-oX/-oS/-oG <file>: Output scan in normal, XML, s|<rIpt kIddi3,
     and Grepable format, respectively, to the given filename.
  -oA <basename>: Output in the three major formats at once
  -v: Increase verbosity level (use -vv or more for greater effect)
  -d: Increase debugging level (use -dd or more for greater effect)
  --reason: Display the reason a port is in a particular state
  --open: Only show open (or possibly open) ports
  --packet-trace: Show all packets sent and received
  --iflist: Print host interfaces and routes (for debugging)
  --log-errors: Log errors/warnings to the normal-format output file
  --append-output: Append to rather than clobber specified output files
  --resume <filename>: Resume an aborted scan
  --stylesheet <path/URL>: XSL stylesheet to transform XML output to HTML
  --webxml: Reference stylesheet from Nmap.Org for more portable XML
  --no-stylesheet: Prevent associating of XSL stylesheet w/XML output
MISC:
  -6: Enable IPv6 scanning
  -A: Enable OS detection, version detection, script scanning, and traceroute
  --datadir <dirname>: Specify custom Nmap data file location
  --send-eth/--send-ip: Send using raw ethernet frames or IP packets
  --privileged: Assume that the user is fully privileged
  --unprivileged: Assume the user lacks raw socket privileges
  -V: Print version number
  -h: Print this help summary page.
EXAMPLES:
  nmap -v -A scanme.nmap.org
  nmap -v -sn 192.168.0.0/16 10.0.0.0/8
  nmap -v -iR 10000 -Pn -p 80

常见命令展示

1) 获取远程主机的系统类型及开放端口

nmap -sS -P0 -sV -O <target>

这里的 < target > 可以是单一 IP, 或主机名，或域名，或子网

-sS TCP SYN 扫描 (又称半开放,或隐身扫描)

-P0 允许你关闭 ICMP pings.

-sV 打开系统版本检测

-O 尝试识别远程操作系统

其它选项:

-A 同时打开操作系统指纹和版本检测

-v 详细输出扫描情况.

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1

nmap -sS -P0 -A -v < target >

2) 列出开放了指定端口的主机列表

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nmap -sT -p 80 -oG – 192.168.1.* | grep open

3) 在网络寻找所有在线主机

nmap -sP 192.168.0.*

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或者也可用以下命令:

nmap -sP 192.168.0.0/24

指定 subnet

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4) Ping 指定范围内的 IP 地址

nmap -sP 192.168.1.100-254

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5) 在某段子网上查找未占用的 IP

nmap -T4 -sP 192.168.2.0/24 && egrep “00:00:00:00:00:00″ /proc/net/arp

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6) 在局域网上扫找 Conficker 蠕虫病毒

nmap -PN -T4 -p139,445 -n -v –script=smb-check-vulns –script-args safe=1 192.168.0.1-254

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7) 扫描网络上的恶意接入点 （rogue APs）.

nmap -A -p1-85,113,443,8080-8100 -T4 –min-hostgroup 50 –max-rtt-timeout

2000 –initial-rtt-timeout 300 –max-retries 3 –host-timeout 20m

–max-scan-delay 1000 -oA wapscan 10.0.0.0/8

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8 ) 使用诱饵扫描方法来扫描主机端口

sudo nmap -sS 192.168.0.10 -D 192.168.0.2

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9) 为一个子网列出反向 DNS 记录

nmap -R -sL 209.85.229.99/27 | awk ‘{if($3==”not”)print”(“$2″) no PTR”;else print$3″ is “$2}’ | grep ‘(‘

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10) 显示网络上共有多少台 Linux 及 Win 设备?

sudo nmap -F -O 192.168.0.1-255 | grep “Running: ” > /tmp/os; echo “$(cat /tmp/os | grep Linux

| wc -l) Linux device(s)”; echo “$(cat /tmp/os | grep Windows | wc -l) Window(s) device”

【更多参考】

Linux网络探测和安全审核工具 nmap使用详解