ping命令

ping命令是我们最常用的命令之一一般用于侦测本机到目标主机的网络是否通畅。其使用方法是ping ip地址使用方法如下[rootlocalhost ~]# ping 120.55.94.78 PING 120.55.94.78 (120.55.94.78) 56(84) bytes of data. 64 bytes from 120.55.94.78: icmp_seq1 ttl128 time11.0 ms 64 bytes from 120.55.94.78: icmp_seq2 ttl128 time17.3 ms 64 bytes from 120.55.94.78: icmp_seq3 ttl128 time16.2 ms 64 bytes from 120.55.94.78: icmp_seq4 ttl128 time10.6 ms 64 bytes from 120.55.94.78: icmp_seq5 ttl128 time10.2 ms 64 bytes from 120.55.94.78: icmp_seq6 ttl128 time18.7 ms 64 bytes from 120.55.94.78: icmp_seq7 ttl128 time15.8 ms 64 bytes from 120.55.94.78: icmp_seq8 ttl128 time10.8 ms 64 bytes from 120.55.94.78: icmp_seq9 ttl128 time10.8 ms 64 bytes from 120.55.94.78: icmp_seq10 ttl128 time11.5 ms如果目标网络不可达ping命令会一直发送而无输出结果直到我们按 Ctrl C 中断才会统计结果。[rootlocalhost ~]# ping 120.55.94.79 PING 120.55.94.79 (120.55.94.79) 56(84) bytes of data. ^C^C --- 120.55.94.79 ping statistics --- 578 packets transmitted, 0 received, 100% packet loss, time 577119msWindows 系统上这种情况下ping 命令会返回超时的包数量而不是一直阻塞。且在 Linux 系统上 ping 命令是一直发送数据包直到人工主动中断而 Windows 机器上默认会发送 4 个数据包后停止如果想一直发送而不停止可以使用-t选项。当然ping命令的目标也可以是一个域名这样通过 ping 这个域名我们可以得到这个域名解析后的 ip 地址[rootlocalhost ~]# ping www.baidu.com PING www.a.shifen.com (61.135.169.121) 56(84) bytes of data. 64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq1 ttl128 time30.3 ms 64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq2 ttl128 time28.8 ms 64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq3 ttl128 time29.0 ms 64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq4 ttl128 time31.9 ms 64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq5 ttl128 time28.8 ms 64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq6 ttl128 time27.8 ms 64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq7 ttl128 time29.0 ms ^C --- www.a.shifen.com ping statistics --- 7 packets transmitted, 7 received, 0% packet loss, time 6011ms rtt min/avg/max/mdev 27.822/29.430/31.968/1.244 ms我们这里得到www.baidu.com对应的 ip 地址是61.135.169.121。ping 命令是通过发送 ICMP 数据包来实现的。