MAC address and IP address
author:
the IP address of the wangyifei data packet determines which computer the data packet will eventually reach, and the MAC address determines which device will receive the data packet next hop, not necessarily the end
subnet mask has only one effect , Is to divide an IP address into two parts: network address and host address.
Computers in the same network segment have the same subnet mask, and the computer's gateway is the exit to other network segments, which is the router interface address. The address used by the router interface can be any address in the network segment, but usually the first available address or the last available address of the network segment is used to avoid conflicts with computer addresses in the network as much as possible.
Class A address 1-126 127 is reserved network segment
Class B
address 128-191 Class C address 192-223
Special address
127.0.0.1 : is the local loopback address, refers to the local address, generally used for testing.
For example,
known IP address 191.23.181.13
subnet mask 255.255.192.0
seeking network address network address broadcast address host address
all
turned into a binary IP address 10111111.00010111.10110101.00001101
subnet mask 1111111. 11111111.11000000.00000000
network address is from the subnet mask 1 and 0 The junction corresponds to the junction of the IP address.
The numbers after the junction all become 0
, which is 10111111.00010111.10000000.00000000
, which is the network address 191.23.128.0. The
broadcast address is the junction of the corresponding IP address from the junction of the subnet mask 1 and 0
. The following numbers all become 1
, which is 10111111.00100111.10111111.11111111
which is 191.23.191.255
The host address is the junction of the corresponding IP address from the junction of the subnet mask 1 and 0.
The numbers before the junction all become 0
, which is 00000000.00000000.00110101.00001101
, which is 0.0.53.13
