Divide the network number and what is the network number

ip:mask:

The former address is converted into binary.

Subnet mask. Convert to binary:

IP address. The first 24 bits remain unchanged, and the last 8 bits copy the last 8 bits in the subnet mask, i.e., each"."symbol as a unit, if the second remainder".

And the third"."If the numbers in are not all 1, then the last 16 bits of the subnet mask are copied to the last 16 bits of the IP to get a new one"ip"The address is the network number.

According to the above operation rules, the result of the operation is , which is converted to decimal system.

then is. <>

ip:mask:

The former address is converted into binary.

Subnet mask. Convert to binary:

IP address. The first 24 bits remain unchanged, and the last 8 bits copy the last 8 bits in the subnet mask, i.e., each"."symbol as a unit, if the second remainder".

And the third"."If the numbers in are not all 1, then the last 16 bits of the subnet mask are copied to the last 16 bits of the IP to get a new one"ip"The address is the network number.

According to the above operation rules, the result of the operation is , which is converted to decimal system.

then is. <>

1. The standard network number is that Class A is the first 8 digits.

Category B is in the top 16.

Category C is in the top 24.

Here's an example.

For example, because it is a Class B address, the bit represented is the bit of the network number, and the bit represented after it is the host bit, and Class A and Class C have the same structure as the example, but the number of bits is different.

2. If it's not standard, it's going to be subnetted, it's different. It depends on the number of digits that follow.

For example, the number of bits of the network number of the 26th generation of Huaichang table is 26 digits, and the remaining 6 digits are the host number; The first 24 bits are the standard network number, and the last two bits are separated from the host gas family number for the division of subnets, and are also divided into network numbers.

This is someone else's example:

If you convert the subnet mask to 2 decimal numbers, then you can see that the number of bits of the host number part is converted into the subnet mask part m=5 (this 5 is the number of 1 in 11111000 obtained by converting 248 into 2 decimal numbers). m=5 to calculate the number of hosts in each subnet that can be reduced in this lan: it is 2 to the 5th power...

Count 32 units (host).

Continue: Subnet No. 1 is Subnet No. 2 Subnet No. 3 is Subnet No. 4 is Subnet No. 5 is Subnet No. 6 is Subnet No. 7 is Subnet No. 8 is Pi Ming.

Now you see, which subnet is your host in? The answer is: No. 4!!

ip:mask:

Subnet mask converted to binary:

The first 24 bits of the IP address remain unchanged, and the last 8 bits of the subnet mask are copied over, i.e., each"."symbol as a unit, if second"."And the third".

If the numbers in are not all 1, then the 16 bits of the subnet mask are copied to the last 16 bits of the IP to get a new one"ip"The address is the network number.

According to the above operation rules, the result of the operation is , and the conversion to decimal system is.

The NSID is a string of numbers plus "."The suffix domain name consists of the user's network information communication number (such as) based on the network number information communication system platform (such as. The network number can not only be regarded as the user's identity on the Internet, but also can be used as the user's personalized, intelligent and multi-functional information and communication software application system on the Internet.

Through the network number they hold, users can obtain platform services that focus on accurate network information distribution, including communication, display and application of good aftermath.

Every host and router on the Internet has an IP address, and the IP address contains the network number and the host number, and this combination is unique. In principle, no two machines on the Internet will have the same IP address. All IP addresses are 32 bits long and are used for the source and destination domains of IP packets.

The first bit of a Class A address is always 0, and the 8 bits are assigned to the network number and the 24 bits are assigned to the host number.

The first two digits of a Class B address are always 10, with 16 bits assigned to the network number and 16 bits assigned to the host number.

The first three digits of a Class C address are always 110, with 24 bits assigned to the network number and 8 bits assigned to the host number.

The first four digits of a Class D address are always 1110.

The first five digits of a Class E address are always 11110.

The network number is managed by a not-for-profit organization under the name of ICANN to avoid conflicts. At the same time, ICANN delegates a portion of the address space to various regional authorities, which in turn assign IP addresses to ISPs and other companies.

The original intention of the IP address classification method is to facilitate the design of routing protocols, and only from the first characteristic bit of the IP address can determine which type of network it belongs to. However, this classification method makes it impossible to maximize the use of address space, and with the rapid expansion of the Internet, the problem of address shortage is becoming more and more prominent.

In order to maximize the use of IP addresses, a network can be divided into multiple subnets, and the structure of IP addresses is divided into three parts: network number, subnet number, and host number. The network number and subnet number uniquely identify a network.

Use the subnet mask to determine which parts of the IP address belong to the network number and subnet number, and which parts belong to the host number. The part with a subnet mask of 1 corresponds to the network number and subnet number of the IP address, and the part with a subnet mask of 0 corresponds to the host number. The division of subnets improves the utilization rate of IP addresses and alleviates the problem of IP address shortage to a certain extent.