Wireshark use

Address resolution protocol , namely ARP（Address Resolution Protocol）, It's based on IP Address gets a physical address TCP/IP agreement . When the host sends the information, it will include the target IP Address of the ARP Request broadcast to all hosts on the LAN , And receive the return message , To determine the physical address of the target ; After receiving the return message, it will be IP The address and physical address are stored in the machine ARP Cache and keep it for a certain time , The next time you ask for it, look it up directly ARP Cache to save resources .
In general , image A Many of these IP Your server is routed like this ： If you have one IP On the same subnet as the other party , From this IP Contract directly to the other party . If there is no one IP Same subnet as the other party , Just go to the default gateway . In this environment ,A Of 3 individual IP Obviously, both B Belong to different subnets , Then we should go to the default gateway . Could it be A There is something wrong with the communication with the default gateway ？ I started from A On ping Check the gateway , The result is that it makes sense . Is it because the gateway did not forward the packet ？ Or is it ping The request has been forwarded to B 了 , but ping The reply was lost on the way ？ I feel like I have walked into a dead end . Whenever this time comes , I will think of the most trusted teammates ——Wireshark.
（1）ping-n1-l1
（2） Operation steps 1
（3）ping-n1-l2
（4） Operation steps 2
（5）ping-n1-l3
（6） Operation steps 3
n1 Refer to ping The number of entries
l3 Is the number of bytes , It can be distinguished by the number of bytes ping Outgoing interval .
Right click the interface , You can use the interface content as a filter .(ip.dst == 192.168.25.14) && (ip.src == 192.168.25.14)