IPv4 数据报的最大大小为 65535 字节,这已经远远超过了以太网的 MTU,而且有些网络还会开启巨帧(Jumbo Frame)能达到 9000 字节。 当一个 IP 数据包大于 MTU 时,IP 会把数据报文进行切割为多个小的片段(小于 MTU),使得这些小的报文可以通过链路层进行传输
ICMP协议解析:
node2:/root#ping -c 1 -s 30 192.168.137.2
PING 192.168.137.2 (192.168.137.2) 30(58) bytes of data.
38 bytes from 192.168.137.2: icmp_seq=1 ttl=64 time=0.534 ms
--- 192.168.137.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.534/0.534/0.534/0.000 ms
You have mail in /var/spool/mail/root
![](https://img-blog.csdnimg.cn/20200321144954455.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW95YW5namlhbjcyNA==,size_16,color_FFFFFF,t_70)
![](https://img-blog.csdnimg.cn/20200321145009138.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW95YW5namlhbjcyNA==,size_16,color_FFFFFF,t_70)
![](https://img-blog.csdnimg.cn/20200321145026397.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW95YW5namlhbjcyNA==,size_16,color_FFFFFF,t_70)