在运维中，我们经常需要测试一下IP或者域名的延迟，一般直接PING 域名或IP即可。
这种 PING 实际上是走的ICMP协议，其实我们用的最多的是TCP协议。如果直接测试TCP协议的网络延迟，应该是更准确的！
下面介绍一款工具，TCPing，不仅可以测得TCP协议的延迟，还能检测端口的连通情况。对于一些禁PING的域名或者IP，我可以直接利用TCPing来查看延迟情况！
Windows版
下载地址：tcping.exe – 通过 TCP 连接执行 ping 操作 (elifulkerson.com)
安装步骤：下载tcping64复制文件到 C:\Windows\System32\ 和SysWOW64即可！
使用方法：打开CMD命令控制台，输入 tcping
NAME
tcping - simulate "ping" over tcp by establishing a connection to network hosts.
Measures the time for your system to [SYN], receive the target's [SYN][ACK] and send [ACK]. Note that the travel time for
the last ACK is not included - only the time it takes to be put on the wire a tthe sending end.
SYNOPSIS
tcping [-tdsvf46] [-i interval] [-n times] [-w interval] [-b n] [-r times][-j depth] [--tee filename] [-f] destination [port]
DESCRIPTION
tcping measures the time it takes to perform a TCP 3-way handshake (SYN, SYN/ACK, ACK) between itself and a remote host.
The travel time of the outgoing final ACK is not included, only the (minimal) amount of time it has taken to drop it on
the wire at the near end. This allows the travel time of the (SYN, SYN/ACK) to approximate the travel time of the
ICMP (request, response) equivalent.
OPTIONS
-4 Prefer using IPv4
-6 Prefer using IPv6
-t ping continuously until stopped via control-c
-n count
send _count_ pings and then stop. Default 4.
-i interval
Wait _interval_ seconds between pings. Default 1. Decimals permitted.
-w interval
Wait _interval_ seconds for a response. Default 2. Decimals permitted.
-d include date and time on every output line
-f Force sending at least one byte in addition to making the connection.
-g count
Give up after _count_ failed pings.
-b type
Enable audible beeps.
'-b 1' will beep "on down". If a host was up, but now its not, beep.
'-b 2' will beep "on up". If a host was down, but now its up, beep.
'-b 3' will beep "on change". If a host was one way, but now its the other, beep.
'-b 4' will beep "always".
-c only show output on a changed state
-r count
Every _count_ pings, we will perform a new DNS lookup for the host in case it changed.
-s Exit immediately upon a success.
-v Print version and exit.
-j Calculate jitter. Jitter is defined as the difference between the last response time and the historical average.
-js depth
Calculate jitter, as with -j but with an optional _depth_ argument specified. If _depth_ is specified tcping will
use the prior _depth_ values to calculate a rolling average.
--tee _filename_
Duplicate output to the _filename_ specified. Windows can still not be depended upon to have a useful command line
environment. Don't tease me, *nix guys.
--append
When using --tee, append to rather than overwrite the output file.
--file
Treat the "destination" option as a filename. That file becomes a source of destinations, looped through on a
line by line basis. Some options don't work in this mode and statistics will not be kept.
destination
A DNS name, an IP address, or (in "http" mode) a URL.
Do not specify the protocol ("http://") in "http" mode. Also do not specify server port via ":port" syntax.
For instance: "tcping http://www.elifulkerson.com:8080/index.html" would fail
Use the style: "tcping www.elifulkerson.com/index.html 8080" instead.
port
A numeric TCP port, 1-65535. If not specified, defaults to 80.
--header
include a header with the command line arguments and timestamp. Header is implied if using --tee.
HTTP MODE OPTIONS
-h Use "http" mode. In http mode we will attempt to GET the specified document and return additional values including
the document's size, http response code, kbit/s.
-u In "http" mode, include the target URL on each output line.
--post Use POST instead of GET in http mode.
--head Use HEAD instead of GET in http mode.
--get Shorthand to invoke "http" mode for consistency's sake.
--proxy-server _proxyserver_
Connect to _proxyserver_ to request the url rather than the server indicated in the url itself.
--proxy-port _port_
Specify the numeric TCP port of the proxy server. Defaults to 3128.
--proxy-credentials username:password
Specify a username:password pair which is sent as a 'Proxy-Authorization: Basic' header.
RETURN VALUE
tcping returns 0 if all pings are successful, 1 if zero pings are successful and 2 for mixed outcome.
BUGS/REQUESTS
Please report bugs and feature requests to the author via contact information on http://www.elifulkerson.com
AVAILABILITY
tcping is available at http://www.elifulkerson.com/projects/tcping.php
Linux版
先apt或yum安装tcptraceroute、bc这两个工具，然后执行
yum install -y tcptraceroute
yum install -y bc
cd /usr/bin
wget http://www.vdberg.org/~richard/tcpping
chmod +x tcpping mv tcpping tcping
tcpping v1.7 Richard van den Berg <richard@vdberg.org>
Usage: tcping [-d] [-c] [-C] [-w sec] [-q num] [-x count] ipaddress [port]
-d print timestamp before every result
-c print a columned result line
-C print in the same format as fping's -C option
-w wait time in seconds (defaults to 3)
-r repeat every n seconds (defaults to 1)
-x repeat n times (defaults to unlimited)
See also: man tcptraceroute
开源项目地址：GitHub – cloverstd/tcping: ping over a tcp connection
