我正在使用ubuntu 13.10和
我之前使用ping来检查服务器是否已启动/关闭.
我之前使用ping来检查服务器是否已启动/关闭.
有人可以帮助我理解,因为我找不到任何解释这个的东西
我做了通常的ping命令
ping 8.8.8.8
输出没有谷歌域名
64 bytes from 8.8.8.8: icmp_seq=1 ttl=48 time=35.9 ms
请注意IP中的尾随.(期间)
ping 8.8.8.8.
谷歌域名输出
64 bytes from google-public-dns-a.google.com (8.8.8.8): icmp_seq=1 ttl=48 time=35.3 ms
输出:
developer@chnPHP006:~$ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. 64 bytes from 8.8.8.8: icmp_seq=1 ttl=48 time=35.9 ms 64 bytes from 8.8.8.8: icmp_seq=2 ttl=48 time=35.7 ms 64 bytes from 8.8.8.8: icmp_seq=3 ttl=48 time=46.2 ms 64 bytes from 8.8.8.8: icmp_seq=4 ttl=48 time=36.6 ms ^C --- 8.8.8.8 ping statistics --- 4 packets transmitted,4 received,0% packet loss,time 3005ms rtt min/avg/max/mdev = 35.779/38.658/46.276/4.415 ms developer@chnPHP006:~$ping 8.8.8.8. PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. 64 bytes from google-public-dns-a.google.com (8.8.8.8): icmp_seq=1 ttl=48 time=35.3 ms 64 bytes from google-public-dns-a.google.com (8.8.8.8): icmp_seq=2 ttl=48 time=35.1 ms 64 bytes from google-public-dns-a.google.com (8.8.8.8): icmp_seq=3 ttl=48 time=36.1 ms 64 bytes from google-public-dns-a.google.com (8.8.8.8): icmp_seq=4 ttl=48 time=35.8 ms ^C --- 8.8.8.8 ping statistics --- 4 packets transmitted,time 3001ms rtt min/avg/max/mdev = 35.128/35.631/36.145/0.441 ms
尾随时间在ping命令中有什么不同?
更新:
这只发生在Ubuntu系统上,而不是在centos / Debian中.
其他Ex:
developer@chnPHP006:~$ping 198.252.206.16 PING 198.252.206.16 (198.252.206.16) 56(84) bytes of data. 64 bytes from 198.252.206.16: icmp_seq=1 ttl=52 time=258 ms 64 bytes from 198.252.206.16: icmp_seq=2 ttl=52 time=258 ms 64 bytes from 198.252.206.16: icmp_seq=3 ttl=52 time=273 ms ^C --- 198.252.206.16 ping statistics --- 3 packets transmitted,3 received,time 2000ms rtt min/avg/max/mdev = 258.144/263.339/273.598/7.278 ms developer@chnPHP006:~$ping 198.252.206.16. PING 198.252.206.16 (198.252.206.16) 56(84) bytes of data. 64 bytes from stackoverflow.com (198.252.206.16): icmp_seq=1 ttl=52 time=259 ms 64 bytes from stackoverflow.com (198.252.206.16): icmp_seq=2 ttl=52 time=267 ms 64 bytes from stackoverflow.com (198.252.206.16): icmp_seq=3 ttl=52 time=271 ms ^C --- 198.252.206.16 ping statistics --- 7 packets transmitted,6 received,14% packet loss,time 6000ms rtt min/avg/max/mdev = 258.292/264.777/274.093/6.447 ms
通常,尾随点用于表示使用的主机名是完全限定的域名(在DNS根目录下).
原文链接:https://www.f2er.com/ubuntu/348078.html附加点将阻止搜索域被附加到DNS查找中的(短)主机名.为什么它会在你的IP地址示例中得到结果,我不知道.
它通常可能是带点的主机名.也被解释为FQDN检测到IP地址的十进制表示(四个数字[0-255]由点分隔)时除外,但是当尾随点被添加到IP地址即匹配规则失败.
如果您的搜索域是example.com和www.example.com的A记录.存在:
ping www
应该解决:
ping www.example.com.
和您的网络服务器的A记录,并导致一些ICMP数据包被发送到您的网络服务器.
ping www.
会失败,因为AFAIK没有顶级域名www