Basic Principles of Network Communication - Diagram

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ARP（Address Resolution Protocol）

Address Resolution Protocol A protocol for obtaining physical addresses
based on addresses .IPTCP/IP

Process:

When the host sends information, it broadcasts IPthe ARPrequest to all hosts on the network, and receives the return message to determine the physical address of the target;
after receiving the return message, the IPaddress and physical address are stored in the local ARPcache and retained For a certain period of time, the cache is directly queried for the next request ARPto save resources.

condition:

The address resolution protocol is based on the mutual trust of each host in the network. Hosts on the network can send response messages autonomously. When other hosts receive the response message, they will not detect the authenticity of the message and record it in this In this way , an attacker can send a fake response message to a certain host, so that the information sent cannot reach the expected host or reach the wrong host, which constitutes a deception. Commands can be used to query the correspondence between addresses and addresses in the local cache , add or delete static correspondences , and so on.
ARPARP
ARPARP
ARPARPIPMAC