@coolxl #22 本质上好像的确是这样。。。外行人看起来很牛逼 🌺🐔

#32 The nc (or netcat) utility is used for just about anything under the sun involving TCP or UDP. It can open TCP connections, send UDP packets, listen on arbitrary TCP and UDP ports, do port scanning, and deal with both IPv4 and IPv6. Unlike telnet(1), nc scripts nicely, and separates error messages onto standard error instead of sending them to standard output, as telnet(1) does with some.

nc 就是 netcat 简写啊。。。

约？？？ 阿里城~

\#12 第二次总结，不对请指正

---

* 可交互
```bash
telnet <host> <port>
nc -v <host> <port> #-v 加上比较容易分辨端口是否关闭
curl <protocol>://<host>:<port> #protocol 请查看 man curl, 另外 wget 可能类似吧
```

---

* 只检测
```bash
nmap -p <port> <host> #可检测服务版本等，closed 就代表关闭
nping --tcp -p <port> <host> #来自 nmap，RCVD 那行=0 就代表关闭
```

---

* 手头没有
1. netcat
2. socat (netcat's extended design, new implementation)
3. psping
4. paping
5. tcping, 这个貌似原始版本没维护了，然后又有几个新写的版本
6. [Using PowerShell's Test-Connection and Test-NetConnection Cmdlets]( https://blog.techsnips.io/powershell-test-connection/)

支持 -------By 一条只支持 default 语法的回复

@des #13 ```话说有这些还不够用吗``` 就当了解一下，技多不压身。

wiki: https://zh.wikipedia.org/wiki/MacOS_Mojave
10.14.4 18E226 2019 年 3 月 25 日
拿```18E226```去 bt/磁力站一搜就各种下载地址

/usr/bin/python3.5: No module named ensurepip

我手头有的先总结一下:
```bash
nmap -p <port> <host>
telnet <host> <port>
nc <host> <port>
curl telnet://<host>:<port>
```
netcat
psping
tcping, 这个貌似原始版本没维护了，然后又有个别新写的版本
cat 怎么写啊？？？

@Cbdy #9 就是 8 楼那样吗？

@julyclyde #5 正确命令是？

@rrfeng #3 cat??怎么用

@ruiowe #19
a: 不是哪一位，是一半人一半尾的美人鱼
b: 左半边人右半边鱼？
a: 不是左和右，是上和下
...
b: 我们言归正传，那个，你刚才说的这个美人鱼漂亮吗
a: 她不是漂亮不漂亮的问题，她真的是那种，那种很少见的那种...

感觉你们都很 geek 呐 o(￣▽￣)ｄ
@ihciah #13 ```隐藏 w 结果``` 啥意思？
@nanaw #14 ```用 root 权限留个后门``` 建小号？还是很容易被看到记录呀
@sigup #12 是这个吗？ https://github.com/jivoi/openssh-backdoor-kit ； 哎呀，没找到```NSA 之前泄露的工具```呢。
@HuasLeung #11 说不定我就是在做坏事🌺🐔
@guyujiezi #10 ```ssh 隧道``` 和我问的好像没多大关系感觉。不吝赐教

不会测试速度和安全性
```text
Starting Nmap 7.70 ( https://nmap.org ) at 2019-04-19 10:47 CST
Strange read error from 118.89.219.192 (49 - 'Can't assign requested address')
RTTVAR has grown to over 2.3 seconds, decreasing to 2.0
RTTVAR has grown to over 2.3 seconds, decreasing to 2.0
Nmap scan report for 118.89.219.192
Host is up (0.053s latency).
Not shown: 55566 closed ports, 9957 filtered ports
Some closed ports may be reported as filtered due to --defeat-rst-ratelimit
PORT STATE SERVICE VERSION
80/tcp open http Microsoft IIS httpd 8.5
443/tcp open ssl/http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)
1026/tcp open msrpc Microsoft Windows RPC
1027/tcp open msrpc Microsoft Windows RPC
1028/tcp open msrpc Microsoft Windows RPC
1061/tcp open msrpc Microsoft Windows RPC
1433/tcp open ms-sql-s Microsoft SQL Server 2012 11.00.3156
1495/tcp open cvc?
3389/tcp open ms-wbt-server Microsoft Terminal Service
5985/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)
8010/tcp open http Microsoft IIS httpd 8.5
8080/tcp open http Microsoft IIS httpd 8.5
47001/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 1287.22 seconds
```