举荐浏览： 每天学一个 Linux 命令（66）：ss
命令简介
nmap（Network Mapper – 网络映射器）命令用于网络探测和平安审核，是网络摸索工具和端口扫描程序。namp 它能够扫描单主机，也能够疾速扫描大型网络结构。
nmap 输入信息是你所扫描指标的列表，且每个指标都有具体的信息展现，具体的展现信息取决于所应用的选项。该信息中的要害是“乏味的端口表”。该表列出了端口号和协定，服务名称以及状态。状态为关上，已过滤，已敞开或未过滤。
[root@CentOS7-1 ~]# nmap --help
-bash: nmap: command not found
[root@CentOS7-1 ~]# yum install nmap -y
语法格局
nmap [Scan Type...] [Options] {target specification}
选项阐明
-O #激活探测操作
-P0 #只进行扫描，不 ping 主机
-PT #是同 TCP 的 ping
-sV #显示服务版本信息
-sP #ping 扫描，仅发现指标主机是否存活
-ps #发送同步（SYN）报文
-PU #发送 udp ping
-PE #强制执行间接的 ICMPping
-PB #默认模式
-6 #应用 IPv6 地址
-v #详细信息
-d #减少调试信息地输入
-A #应用所有高级扫描选项
--resume #复原（持续上次）停止的扫描
-P #指定要扫描的端口，能够是一个端口，用逗号隔开多个端口，应用“-”示意端口范畴
-e #在多网络接口 Linux 零碎中，指定扫描应用的网络接口
-g #将指定的端口作为源端口进行扫描
--ttl #指定发送的扫描报文的生存期
--packet-trace #显示扫描过程中收发报文统计
--scanflags #设置在扫描报文中的 TCP 标记
--send-eth/--send-ip #应用原始以太网发送 / 结构指定 IP 发送
利用举例
典型的扫描
[root@CentOS7-1 ~]# nmap -A www.baidu.com
Starting Nmap 6.40 (http://nmap.org) at 2021-03-13 04:30 EST
Nmap scan report for www.baidu.com (36.152.44.95)
Host is up (0.012s latency).
Other addresses for www.baidu.com (not scanned): 36.152.44.96
Not shown: 998 filtered ports
PORT STATE SERVICE VERSION
80/tcp open http-proxy sslstrip
|_http-methods: No Allow or Public header in OPTIONS response (status code 302)
| http-robots.txt: 10 disallowed entries
| /baidu /s? /ulink? /link? /home/news/data/ /bh /shifen/
|_/homepage/ /cpro /
|_http-title: xE7x99xBExE5xBAxA6xE4xB8x80xE4xB8x8BxEFxBCx8CxE4xBDxA0xE5xB0xB1xE7x9FxA5xE9x81x93
443/tcp open ssl/http-proxy sslstrip
|_http-methods: No Allow or Public header in OPTIONS response (status code 302)
| http-robots.txt: 10 disallowed entries
| /baidu /s? /ulink? /link? /home/news/data/ /bh /shifen/
|_/homepage/ /cpro /
|_http-title: Site doesn't have a title (text/html).
| ssl-cert: Subject: commonName=baidu.com/organizationName=Beijing Baidu Netcom Science Technology Co., Ltd/stateOrProvinceName=beijing/countryName=CN
| Not valid before: 2020-04-02T06:04:58+00:00
|_Not valid after: 2021-07-26T04:31:02+00:00
|_ssl-date: 2021-03-16T03:14:21+00:00; +2d17h43m18s from local time.
| tls-nextprotoneg:
|_ http/1.1
Warning: OSScan results may be unreliable because we could not find at least 1 open and 1 closed port
Device type: specialized|switch
Running (JUST GUESSING): AVtech embedded (88%), HP embedded (86%)
OS CPE: cpe:/h:hp:procurve_switch_4000m
Aggressive OS guesses: AVtech Room Alert 26W environmental monitor (88%), HP 4000M ProCurve switch (J4121A) (86%)
No exact OS matches for host (test conditions non-ideal).
Network Distance: 10 hops
TRACEROUTE (using port 80/tcp)
HOP RTT ADDRESS
1 0.97 ms 192.168.1.1
2 4.96 ms 100.106.0.1
3 ... 9
10 15.25 ms 36.152.44.95
OS and Service detection performed. Please report any incorrect results at http://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 37.64 seconds
TCP 端口扫描
[root@CentOS7-1 ~]# nmap -sT 192.168.1.100
Starting Nmap 6.40 (http://nmap.org) at 2021-03-13 04:32 EST
Nmap scan report for 192.168.1.100
Host is up (0.00037s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds
扫描 1 -65535
[root@CentOS7-1 ~]# nmap -p 1-65535 -T4 -A -v 192.168.1.100
Starting Nmap 6.40 (http://nmap.org) at 2021-03-13 04:33 EST
NSE: Loaded 110 scripts for scanning.
NSE: Script Pre-scanning.
Initiating Parallel DNS resolution of 1 host. at 04:33
Completed Parallel DNS resolution of 1 host. at 04:33, 0.00s elapsed
Initiating SYN Stealth Scan at 04:33
Scanning 192.168.1.100 [65535 ports]
Discovered open port 22/tcp on 192.168.1.100
Discovered open port 19999/tcp on 192.168.1.100
Completed SYN Stealth Scan at 04:33, 6.82s elapsed (65535 total ports)
Initiating Service scan at 04:33
Scanning 2 services on 192.168.1.100
Completed Service scan at 04:33, 19.10s elapsed (2 services on 1 host)
Initiating OS detection (try #1) against 192.168.1.100
NSE: Script scanning 192.168.1.100.
Initiating NSE at 04:34
Completed NSE at 04:34, 0.14s elapsed
Nmap scan report for 192.168.1.100
Host is up (0.000032s latency).
Not shown: 65533 closed ports
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 7.4 (protocol 2.0)
| ssh-hostkey: 2048 37:71:8e:4a:db:cc:ac:29:f2:a2:20:93:23:8c:f6:e8 (RSA)
|_256 cc:4b:7d:b6:59:0f:77:83:a9:a5:32:70:4e:87:0d:41 (ECDSA)
19999/tcp open unknown
1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at http://www.insecure.org/cgi-bin/servicefp-submit.cgi :
SF-Port19999-TCP:V=6.40%I=7%D=3/13%Time=604C86FA%P=x86_64-redhat-linux-gnu
SF:%r(GenericLines,190,"HTTP/1.1x20400x20Badx20RequestrnConnection:
SF:x20closernServer:x20NetDatax20Embeddedx20HTTPx20Serverx20v1.29
SF:.3rnAccess-Control-Allow-Origin:x20*rnAccess-Control-Allow-Creden
SF:tials:x20truernContent-Type:x20text/plain;x20charset=utf-8rnDate
SF::x20Sat,x2013x20Marx202021x2009:33:46x20GMTrnCache-Control:x20
SF:no-cache,x20no-store,x20must-revalidaternPragma:x20no-cachernExp
SF:ires:x20Sat,x2013x20Marx202021x2009:33:47x20GMTrnContent-Length
SF::x2027rnrnIx20don'tx20understandx20you...rn")%r(GetRequest
SF:,5580,"HTTP/1.1x20200x20OKrnConnection:x20closernServer:x20Net
SF:Datax20Embeddedx20HTTPx20Serverx20v1.29.3rnAccess-Control-Allow
SF:-Origin:x20*rnAccess-Control-Allow-Credentials:x20truernContent-
SF:Type:x20text/html;x20charset=utf-8rnDate:x20Tue,x2009x20Febx202
SF:021x2010:11:54x20GMTrnCache-Control:x20publicrnExpires:x20Sun,
SF:x2014x20Marx202021x2009:33:46x20GMTrnContent-Length:x2085228rn
SF:rn<!doctypex20html><htmlx20lang="en"><head><title>netdatax20dash
SF:board</title><metax20name="application-name"x20content="netdata">
SF:<metax20http-equiv="Content-Type"x20content="text/html;x20charset
SF:=utf-8"/><metax20charset="utf-8"><metax20http-equiv="X-UA-Compati
SF:ble"x20content="IE=edge,chrome=1"><metax20name="viewport"x20con
SF:tent="width=device-width,initial-scale=1"><metax20name="apple-mobil
SF:e-web-app-capable"x20content="yes"><metax20name="apple-mobile-web
SF:-app-status-bar-style"x20content="black-translucent"><metax20name=
SF:"author"x20content="costa@tsaousis.gr"><linkx20rel="icon"x20h
SF:ref="data:image/x-icon;base64,iVBORw0KGgoAAA")%r(HTTPOptions,1C7,"HTTP
SF:/1.1x20200x20OKrnConnection:x20closernServer:x20NetDatax20Emb
SF:eddedx20HTTPx20Serverx20v1.29.3rnAccess-Control-Allow-Origin:x2
SF:0*rnAccess-Control-Allow-Credentials:x20truernContent-Type:x20te
SF:xt/plain;x20charset=utf-8rnDate:x20Sat,x2013x20Marx202021x2009:
SF:33:47x20GMTrnAccess-Control-Allow-Methods:x20GET,x20OPTIONSrnAcc
SF:ess-Control-Allow-Headers:x20accept,x20x-requested-with,x20origin,x
SF:20content-type,x20cookie,x20pragma,x20cache-control,x20x-auth-token
SF:rnAccess-Control-Max-Age:x201209600rnContent-Length:x202rnrnO
SF:K");
Device type: general purpose
Running: Linux 3.X
OS CPE: cpe:/o:linux:linux_kernel:3
OS details: Linux 3.7 - 3.9
Uptime guess: 0.241 days (since Fri Mar 12 22:47:04 2021)
Network Distance: 0 hops
TCP Sequence Prediction: Difficulty=261 (Good luck!)
IP ID Sequence Generation: All zeros
NSE: Script Post-scanning.
Initiating NSE at 04:34
Completed NSE at 04:34, 0.00s elapsed
Read data files from: /usr/bin/../share/nmap
OS and Service detection performed. Please report any incorrect results at http://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 29.46 seconds
Raw packets sent: 65647 (2.891MB) | Rcvd: 131302 (5.519MB)
UDP 端口扫描
[root@CentOS7-1 ~]# nmap -sU 192.168.1.100
Starting Nmap 6.40 (http://nmap.org) at 2021-03-13 04:34 EST
Nmap scan report for 192.168.1.100
Host is up (0.0000040s latency).
All 1000 scanned ports on 192.168.1.100 are closed
Nmap done: 1 IP address (1 host up) scanned in 1.65 seconds
每天学一个 Linux 命令（64）：ifconfig
每天学一个 Linux 命令（65）：netstat