Unicast, multicast and broadcast of IP network communication

One 、 Judge whether the two devices are in the same LAN

View the... Of two devices ip4 Address and Subnet mask MASK.

• if MASK Dissimilarity , Is not in the same LAN .
• if MASK equally , Separate calculation IP&MASK. If they are the same , On the same LAN , Otherwise, they are not on the same LAN .

Two 、 unicast 、 The difference between multicast and broadcast

unicast ： In the same LAN , Point to point communication between two devices is unicast communication . stay ifconfig To configure vlan when , Target of end-to-end equipment IP The address must be the same as that configured for the local device IP The address is consistent , And opposite end IP With the local IP In the same LAN .

Multicast ： Within the reach of the same network , A network device communicates with some devices concerned with its data . stay ifconfig To configure vlan when , Target of end-to-end equipment IP Is the specified multicast address （224.0.0.0~239.255.255.255）, And local IP And the opposite end IP In the same LAN . When the local device obtains data, it needs to filter the multicast address separately .

radio broadcast ： Within the reach of the same network , A network device communicates with all devices in the network . stay ifconfig To configure vlan when , Target of end-to-end equipment IP by 255.255.255.255 Or can be associated with MASK Just right 255.255.255.255 Directional broadcast address of , And local IP And the opposite end IP In the same LAN .

reference

【1】 How to judge whether two devices are in the same LAN _guojunxiu The blog of

【2】 radio broadcast 、 Multicast 、 Unicast differences and connections _ Internet of things Lao Wang's blog -CSDN Blog _ The difference between unicast multicast and broadcast

【3】 Multicast address classification _Mr. Sun_ The blog of -CSDN Blog _ Multicast address classification