nmap — 网络探测工具和安全/端口扫描器，最主要的还是端口扫描功能。
(1).安装(手机arm处理器也支持)
yum install nmap
(2).官方命令范例(最快的速度和全面扫描)
nmap -A -T4 doc.gaojiufeng.cn
输出结果
Starting Nmap 6.40 ( http://nmap.org ) at 2020-07-13 09:31 CST Nmap scan report for doc.gaojiufeng.cn (47.240.19.5) Host is up (0.098s latency). Not shown: 995 filtered ports PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 6.6.1 (protocol 2.0) | ssh-hostkey: 2048 9b:61:d2:f9:bf:f6:28:28:57:34:d4:33:88:8b:52:2b (RSA) |_256 76:f3:c5:92:f7:c4:84:de:d4:02:e5:18:8d:5c:4e:bb (ECDSA) 80/tcp open http nginx |_http-generator: Z-BlogPHP 1.5.1 Zero |_http-methods: No Allow or Public header in OPTIONS response (status code 405) |_http-title: \xE9\xAB\x98\xE4\xB9\x85\xE5\xB3\xB0's Blog | \xE5\x85\xB3\xE6\xB3\xA8\xE7\x94\x9F\xE6\xB4\xBB\xE3\x80\x81\xE7\xBC\x96\xE7\xA8\x8B\xE3\x80\x81\xE5\xBD\xB1\xE8\xA7\x86\xE3\x80\x81\xE5\x88\x9B\xE4\xB8\x9A\xE7\x9A\x84\xE5... 443/tcp open http nginx |_http-methods: No Allow or Public header in OPTIONS response (status code 302) |_http-title: Did not follow redirect to https://doc.gaojiufeng.cn/ | ssl-cert: Subject: commonName=www.gaojiufeng.cn | Not valid before: 2019-09-20T00:00:00+00:00 |_Not valid after: 2020-12-18T12:00:00+00:00 888/tcp open http nginx |_http-methods: No Allow or Public header in OPTIONS response (status code 405) |_http-title: 403 Forbidden 8888/tcp open sun-answerbook? 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-Port8888-TCP:V=6.40%I=7%D=7/13%Time=5F0BB99A%P=aarch64-redhat-linux-gnu SF:%r(GetRequest,1EE,"HTTP/1\.1\x20302\x20FOUND\r\nContent-Type:\x20text/h SF:tml;\x20charset=utf-8\r\nContent-Length:\x20219\r\nLocation:\x20http:// SF:izj6c2jeancylo0ppo4vz5z:8888/login\r\nSet-Cookie:\x20BT_PANEL_6=;\x20Ex SF:pires=Thu,\x2001-Jan-1970\x2000:00:00\x20GMT;\x20Max-Age=0;\x20Path=/\r SF:\nConnection:\x20close\r\nDate:\x20Mon,\x2013\x20Jul\x202020\x2001:32:0 SF:9\x20GMT\r\n\r\n<!DOCTYPE\x20HTML\x20PUBLIC\x20\"-//W3C//DTD\x20HTML\x2 SF:03\.2\x20Final//EN\">\n<title>Redirecting\.\.\.</title>\n<h1>Redirectin SF:g\.\.\.</h1>\n<p>You\x20should\x20be\x20redirected\x20automatically\x20 SF:to\x20target\x20URL:\x20<a\x20href=\"/login\">/login</a>\.\x20\x20If\x2 SF:0not\x20click\x20the\x20link\.")%r(HTTPOptions,139,"HTTP/1\.1\x20200\x2 SF:0OK\r\nContent-Type:\x20text/html;\x20charset=utf-8\r\nAllow:\x20HEAD,\ SF:x20GET,\x20POST,\x20OPTIONS\r\nSet-Cookie:\x20BT_PANEL_6=24babc55-73eb- SF:4346-b602-b9b47ade9731\.dM1KccF63CNQlSilLKFEsL4XhAo;\x20Expires=Tue,\x2 SF:014-Jul-2020\x2001:32:09\x20GMT;\x20HttpOnly;\x20Path=/\r\nContent-Leng SF:th:\x200\r\nConnection:\x20close\r\nDate:\x20Mon,\x2013\x20Jul\x202020\ SF:x2001:32:09\x20GMT\r\n\r\n")%r(FourOhFourRequest,1EE,"HTTP/1\.1\x20302\ SF:x20FOUND\r\nContent-Type:\x20text/html;\x20charset=utf-8\r\nContent-Len SF:gth:\x20219\r\nLocation:\x20http://izj6c2jeancylo0ppo4vz5z:8888/login\r SF:\nSet-Cookie:\x20BT_PANEL_6=;\x20Expires=Thu,\x2001-Jan-1970\x2000:00:0 SF:0\x20GMT;\x20Max-Age=0;\x20Path=/\r\nConnection:\x20close\r\nDate:\x20M SF:on,\x2013\x20Jul\x202020\x2001:32:10\x20GMT\r\n\r\n<!DOCTYPE\x20HTML\x2 SF:0PUBLIC\x20\"-//W3C//DTD\x20HTML\x203\.2\x20Final//EN\">\n<title>Redire SF:cting\.\.\.</title>\n<h1>Redirecting\.\.\.</h1>\n<p>You\x20should\x20be SF:\x20redirected\x20automatically\x20to\x20target\x20URL:\x20<a\x20href=\ SF:"/login\">/login</a>\.\x20\x20If\x20not\x20click\x20the\x20link\.")%r(G SF:enericLines,42,"HTTP/1\.1\x20400\x20Bad\x20Request\r\nConnection:\x20cl SF:ose\r\nContent-length:\x200\r\n\r\n")%r(RTSPRequest,42,"HTTP/1\.1\x2040 SF:0\x20Bad\x20Request\r\nConnection:\x20close\r\nContent-length:\x200\r\n SF:\r\n")%r(Help,42,"HTTP/1\.1\x20400\x20Bad\x20Request\r\nConnection:\x20 SF:close\r\nContent-length:\x200\r\n\r\n"); Warning: OSScan results may be unreliable because we could not find at least 1 open and 1 closed port Aggressive OS guesses: Crestron XPanel control system (90%), Netgear DG834G WAP or Western Digital WD TV media player (90%), Linux 3.1 (87%), Linux 3.2 (87%), HP P2000 G3 NAS device (87%), AXIS 210A or 211 Network Camera (Linux 2.6) (87%), Android 4.1.1 (85%) No exact OS matches for host (test conditions non-ideal). Network Distance: 20 hops TRACEROUTE (using port 80/tcp) HOP RTT ADDRESS 1 37.29 ms 192.168.1.1 2 ... 3 243.01 ms 113.87.192.1 4 244.23 ms 177.184.37.59.broad.dg.gd.dynamic.163data.com.cn (59.37.184.177) 5 244.26 ms 183.56.65.78 6 244.34 ms 202.97.64.113 7 244.41 ms 202.97.18.253 8 ... 9 244.59 ms 219.158.96.197 10 248.14 ms 219.158.19.66 11 195.86 ms 219.158.103.38 12 302.23 ms 219.158.10.54 13 289.96 ms 202.77.23.26 14 288.44 ms 61.14.201.94 15 287.83 ms 162.245.124.9 16 286.89 ms 47.246.113.234 17 286.25 ms 47.246.115.61 18 285.70 ms 47.246.113.250 19 285.14 ms 11.52.236.13 20 105.31 ms 47.240.19.5 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 191.93 seconds
很快将我网站的端口扫描完毕。但是并没有真正测试出我的操作系统，只是给了可能是哪些操作系统，并且给了可能性占比。最强大的莫过于最后输出的路由追踪，崩溃了，难怪我的服务器这么卡，经过了这么多次的跳转。。
