Subnet division Summary

Subnet division summary there are a lot of questions about subnet division on the Internet, which is also very detailed, that is, a little too complicated. So here I will make a summary based on my own understanding... The benefits of subnet division are not described in detail. After Dividing subnets, IP addresses = network numbers + subnet numbers + host numbers are allocated by dedicated organizations, after the application, the network administrator will divide the network according to their own needs. Assume that an IP address is 40.15.0.0. If the subnet is not divided, the default subnet mask should be 255.255.0.0. The subnet mask for subnet division will change., however, assume that we want to divide two subnets Based on 255.255.0.0 (the subnet number occupies one and the host Space occupies 15), then the subnet mask is 255.255.128.0, the two subnets are 40.15.0.0 and 40.15.128.0, respectively. The subnet number occupies 2 places and the host Space occupies 14 places. The mask is 255.255.192.0 and the subnet number is. 40.15.0.0, 40.15.64.0, 40.15.128.0, and 40.15.192.0 are composed of three or four subnets (the subnet number occupies 2 places and the host Space occupies 14 places). The mask is 255.255.255.192.0, the subnet number is the four five subnets above (the subnet number occupies 3 places, and the host Space occupies 13 places). The mask is 255.255.224.0, the subnet numbers include 40.15.0.0, 40.15.32.0, 40.15.64.0, 40.15.96.0, 40.15.128.0, 40.15.160.0, 40.15.192.0, and 40.15.224.0 ...... explanation: Expand the Third Field of the default subnet mask: the first field of 00000000 is 1, which can represent two subnets (0, 1) the first two digits can be 1, indicating no more than 4 subnets (00, 01, 10, and 11) the first three digits can be 1 to indicate no more than 8 subnets (000, 001, 010, 011, 100, 101, 110, 111 )...... note: If the host space is 0, the multicast address is displayed. If the host space is 1, the broadcast address is displayed.