linux命令学习笔记（54）：ping命令

Linux系统的ping命令是常用的网络命令，它通常用来测试与目标主机的连通性，我们经常会说“ping一下某机器，
看是不是开着”、不能打开网页时会说“你先ping网关地址192.168.1.1试试”。它通过发送ICMP ECHO_REQUEST数据
包到网络主机（send ICMP ECHO_REQUEST to network hosts），并显示响应情况，这样我们就可以根据它输出的
信息来确定目标主机是否可访问（但这不是绝对的）。有些服务器为了防止通过ping探测到，通过防火墙设置了禁
止ping或者在内核参数中禁止ping，这样就不能通过ping确定该主机是否还处于开启状态。
linux下的ping和windows下的ping稍有区别,linux下ping不会自动终止,需要按ctrl+c终止或者用参数-c指定要求完
成的回应次数。
.命令格式：
ping [参数] [主机名或IP地址]
.命令功能：
ping命令用于：确定网络和各外部主机的状态；跟踪和隔离硬件和软件问题；测试、评估和管理网络。如果主机正
在运行并连在网上，它就对回送信号进行响应。每个回送信号请求包含一个网际协议（IP）和 ICMP 头，后面紧跟
一个 tim 结构，以及来填写这个信息包的足够的字节。缺省情况是连续发送回送信号请求直到接收到中断信号
（Ctrl-C）。
ping 命令每秒发送一个数据报并且为每个接收到的响应打印一行输出。ping 命令计算信号往返时间和(信息)包
丢失情况的统计信息，并且在完成之后显示一个简要总结。ping 命令在程序超时或当接收到 SIGINT 信号时结
束。Host 参数或者是一个有效的主机名或者是因特网地址。
.命令参数：
-d 使用Socket的SO_DEBUG功能。
-f 极限检测。大量且快速地送网络封包给一台机器，看它的回应。
-n 只输出数值。
-q 不显示任何传送封包的信息，只显示最后的结果。
-r 忽略普通的Routing Table，直接将数据包送到远端主机上。通常是查看本机的网络接口是否有问题。
-R 记录路由过程。
-v 详细显示指令的执行过程。
<p>-c 数目：在发送指定数目的包后停止。
-i 秒数：设定间隔几秒送一个网络封包给一台机器，预设值是一秒送一次。
-I 网络界面：使用指定的网络界面送出数据包。
-l 前置载入：设置在送出要求信息之前，先行发出的数据包。
-p 范本样式：设置填满数据包的范本样式。
-s 字节数：指定发送的数据字节数，预设值是56，加上8字节的ICMP头，一共是64ICMP数据字节。
-t 存活数值：设置存活数值TTL的大小。
.使用实例：
实例1：ping的通的情况
命令：
ping 192.168.120.205
输出：
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[root@localhost ~]# ping 192.168.120.205
PING 192.168.120.205 (192.168.120.205) () bytes of data.
bytes from 192.168.120.205: icmp_seq= ttl= time=0.720 ms
bytes from 192.168.120.205: icmp_seq= ttl= time=0.181 ms
bytes from 192.168.120.205: icmp_seq= ttl= time=0.191 ms
bytes from 192.168.120.205: icmp_seq= ttl= time=0.188 ms
bytes from 192.168.120.205: icmp_seq= ttl= time=0.189 ms--- 192.168.120.205 ping statistics ---
packets transmitted, received, % packet loss, time 4000ms
rtt min/avg/max/mdev = 0.181/0.293/0.720/0.214 ms
[root@localhost ~]#
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说明：实例2：ping不通的情况
命令：
ping 192.168.120.202
输出：
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[root@localhost ~]# ping 192.168.120.202
PING 192.168.120.202 (192.168.120.202) () bytes of data.
From 192.168.120.204 icmp_seq= Destination Host Unreachable
From 192.168.120.204 icmp_seq= Destination Host Unreachable
From 192.168.120.204 icmp_seq= Destination Host Unreachable
From 192.168.120.204 icmp_seq= Destination Host Unreachable
From 192.168.120.204 icmp_seq= Destination Host Unreachable
From 192.168.120.204 icmp_seq= Destination Host Unreachable--- 192.168.120.202 ping statistics ---
packets transmitted, received, + errors, % packet loss, time 7005ms
, pipe
[root@localhost ~]#
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说明：实例3：ping网关
命令：
ping -b 192.168.120.1
输出：
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[root@localhost ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.120.0 * 255.255.255.0 U eth0
192.168.0.0 192.168.120.1 255.255.0.0 UG eth0
10.0.0.0 192.168.120.1 255.0.0.0 UG eth0
default 192.168.120.240 0.0.0.0 UG eth0
[root@localhost ~]# ping -b 192.168.120.1
PING 192.168.120.1 (192.168.120.1) () bytes of data.
bytes from 192.168.120.1: icmp_seq= ttl= time=2.02 ms
bytes from 192.168.120.1: icmp_seq= ttl= time=1.83 ms
bytes from 192.168.120.1: icmp_seq= ttl= time=1.68 ms
bytes from 192.168.120.1: icmp_seq= ttl= time=1.98 ms
bytes from 192.168.120.1: icmp_seq= ttl= time=1.88 ms--- 192.168.120.1 ping statistics ---
packets transmitted, received, % packet loss, time 4000ms
rtt min/avg/max/mdev = 1.682/1.880/2.020/0.129 ms
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说明：实例4：ping指定次数
命令：
ping -c 192.168.120.206
输出：
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[root@localhost ~]# ping -c 192.168.120.206
PING 192.168.120.206 (192.168.120.206) () bytes of data.
bytes from 192.168.120.206: icmp_seq= ttl= time=1.25 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.260 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.242 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.271 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.274 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.295 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.269 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.270 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.253 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.289 ms--- 192.168.120.206 ping statistics ---
packets transmitted, received, % packet loss, time 9000ms
rtt min/avg/max/mdev = 0.242/0.367/1.251/0.295 ms
[root@localhost ~]#
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说明：实例5：时间间隔和次数限制的ping
命令：
ping -c -i 0.5 192.168.120.206
输出：
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[root@localhost ~]# ping -c -i 0.5 192.168.120.206
PING 192.168.120.206 (192.168.120.206) () bytes of data.
bytes from 192.168.120.206: icmp_seq= ttl= time=1.24 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.235 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.244 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.300 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.255 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.264 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.263 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.331 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.247 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.244 ms--- 192.168.120.206 ping statistics ---
packets transmitted, received, % packet loss, time 4499ms
rtt min/avg/max/mdev = 0.235/0.362/1.241/0.294 ms
[root@localhost ~]# ping -c -i 0.01 192.168.120.206
PING 192.168.120.206 (192.168.120.206) () bytes of data.
bytes from 192.168.120.206: icmp_seq= ttl= time=0.244 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.195 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.219 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.204 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=3.56 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=1.93 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.193 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.193 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.202 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.211 ms--- 192.168.120.206 ping statistics ---
packets transmitted, received, % packet loss, time 90ms
rtt min/avg/max/mdev = 0.193/0.716/3.564/1.080 ms
[root@localhost ~]#
复制代码说明：实例6：通过域名ping公网上的站点
命令：
ping -c www..com
输出：
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peida-VirtualBox ~ # ping -c www..com
PING www..com (211.151.111.30) () bytes of data.
bytes from 211.151.111.30: icmp_req= ttl= time=14.7 ms
bytes from 211.151.111.30: icmp_req= ttl= time=16.4 ms
bytes from 211.151.111.30: icmp_req= ttl= time=15.2 ms
bytes from 211.151.111.30: icmp_req= ttl= time=14.6 ms
bytes from 211.151.111.30: icmp_req= ttl= time=19.9 ms--- www..com ping statistics ---
packets transmitted, received, % packet loss, time 20101ms
rtt min/avg/max/mdev = 14.618/16.192/19.917/1.965 ms
peida-VirtualBox ~ #
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说明：实例7：多参数使用
命令：
ping -i -s -t 192.168.120.206
输出：
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[root@localhost ~]# ping -i -s -t 192.168.120.206
PING 192.168.120.206 (192.168.120.206) () bytes of data.
bytes from 192.168.120.206: icmp_seq= ttl= time=1.99 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.694 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.300 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.481 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.415 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.600 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.411 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.281 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.318 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.362 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.408 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.445 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.397 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.406 ms
bytes from 192.168.120.206: icmp_seq= ttl= time=0.458 ms--- 192.168.120.206 ping statistics ---
packets transmitted, received, % packet loss, time 41999ms
rtt min/avg/max/mdev = 0.281/0.531/1.993/0.404 ms
[root@localhost ~]#
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说明：
-i 发送周期为 3秒 -s 设置发送包的大小为1024 -t 设置TTL值为