Explain in detail the Intranet IP address planning for over 255 computers

Network IP addresses are classified into three categories: ABC, which are covered in the following areas:

Class A: 0.0.0.0-127.255.255.255, whose subnet mask is 255.0.0.0 (another way to label the subnet mask is/8, which is to convert the subnet mask to binary, 8 from the left)

Class B: 128.0.0.0-191.255.255.255. Whose subnet mask is 255.255.0.0 (another way to label the subnet mask is/16, which is to convert the subnet mask to binary, 16 from the left. 1)

Class C: 192.0.0.0-223.255.255.255, whose subnet mask is 255.255.255.0 (another way to label the subnet mask is/24, which is to convert the subnet mask to binary, 24 from the left. 1)

To save space and reduce pen mistakes, the following subnet masks are marked using the/X method. The maximum possible value of X is 32, and the minimum value is 0.

A subnet division problem is also involved:

If ICANN issues you 9. x. x. x, you get a Class A network named 9.0.0.0/8. It may be difficult to manage because the network is too large, so you can divide subnets, it can be divided into 9.1.0.0/16, 9.2.0.0/16, 9.3.0.0/16, and 9.0.0/16, and subdivided into 9.20.1.0/24 and 9.20.2.0/24 ...... of course, you can further split it down.

There is also a problem of subnet merging:

If ICANN issues you 220.220.x.x, according to the standard, you actually get 256 standard class C networks such as 220.220.0.0/24, 220.220.1.0/24, 220.220.255.0/24, and 220.220.255.0/24, what you need is a large network that can accommodate tens of thousands of nodes. You can combine 220.220.x.x into a network, that is, 222.220.0.0/16. This is called CIDR, we will use this later.

The part planned for the private IP address area is exactly the one in ABC:

10.0.0.0-10.255.255.255 (10.0.0.0/8)

172.16.0.0-172.31.255.255 (172.160.0./16-172.31.0.0/16)

192.168.0.0-192.168.255.255 (192.168.0.0/24-192.168.255.0/24)

There are also some special sections such as Section 127, section 169, and section 224-255 of class d e, which are irrelevant to this topic.

Public IP addresses are very valuable resources today, especially in China.

Therefore, many enterprises, institutions, and even internet cafes do not have to use public IP addresses in their internal LAN, so private IP addresses are used. According to the scale, the larger enterprises chose 10. x. x. x, some use 172.16.x.x, smaller internet cafes, the most popular is 192.168.0.x, a standard class C network. Note that this is just a habit, not a rule

Nowadays, Internet cafes are getting bigger and bigger, and a standard class C network can no longer meet the capacity requirements. Many people say that, can I put 192.168.0.x and 192.168.1.x on a single network? Of course! By introducing the concept of CIDR, it is easy to conclude that 192.168.0.0/255.255.254.0, or 192.168.0.0/23, is 192.168.0.x + 192.168.1.x. A total of 512 nodes can be accommodated regardless of the network address and broadcast address. Of course, 192.168.0.0/22, 192.168.0.0/21, 192.168.0.0/20, and 192.168.0.0/16 are all planning methods that can accommodate more nodes.

However, I am not very impressed with CIDR. CIDR is just a method and should not belong to a specification, which brings about some compatibility problems. When I set RRAS in Win2000 (SP2) A few years ago, there was an interface filtering similar to the packet filtering measure. Many of my friends may have the impression that when I defined the target network, it does not recognize networks like 218.4.0.0/255.255.0.0, which means the subnet mask is invalid, you must manually configure 256 target networks such as 218.4.0.0/24, 218.4.1.0/24, 218.4.3.0/24, and 218.4.255.0/24, because the class c ip address only recognizes the subnet mask such as 255.255.255.0, And the IP address audit in IIS also has such a situation, Khan ~~~

In addition, why are so many friends asking, "How do I plan IP addresses for over 254 hosts in an Internet cafe, it is because it involves the computation after CIDR subnet merging. Because the network base is not enough, many friends don't understand it. It doesn't matter if you don't understand it. You really don't need to understand it. Let's look at the topic.

Why are all pushed to C classes like 192.168.x.x?

10. x (255.0.0.0) and 172.16.x.x ~ 172.31.x.x (255.255.0.0) is not a big concept here?

10.0.0.0/8 and 172.16.0.0/16-172.31.0.0/16 are not good options? Absolutely compliant with the standards, absolutely no rebellion, some people say that such a large network must have broadcast storm cloud, this is a bit funny. Let's not discuss what the broadcast storm itself is. 10.0.0.0/8 can indeed accommodate 16777216 nodes, but do you really have 16777216 hosts? The broadcast volume is indeed proportional to the number of hosts in the LAN. It has nothing to do with the number of hosts that the LAN can accommodate, in addition, in the software and hardware environment such as Internet cafes, as long as the device and link are normal and the client is healthy, there will be no broadcast storm. In many people's homes, the default IP address of the ADSL Broadband CAT (Zhukang ut300r) is 10.0.0.138, And the mask is 255.0.0.0. If the routing mode is enabled, set your computer to 10. x. x. if one of them exists in the LAN with a very large range but only two nodes, the result is no explosion? Of course, if you are really worried, you can use 10.0.0.0/255.255.254.0, you can use the IP address 10.0.0.0-10.0.1.255, there is no problem with this solution.

You are tired of 10. x. x. x, you are also tired of 172.16.x.x-172.31.x.x, and you are tired of 192.168.x.x. Then, on behalf of ICANN, I can assign you a network with a personalized IP address.

The rules only once again support my own opinion on "rebellion". The Internet cafe uses 1.1.1.x, a lucky, memorable and personalized network, which is completely feasible and has side effects? Almost none. I just checked that the IP address belongs to General Electric Appliance Company in New Jersey, USA. Do you really need to visit the company? Or is there a customer in your internet cafe who is going to work there to consult their website? Of course, if someone on the Internet accesses 1.1.1.x, it will not go to you. It will only go to 1.1.1.x, because vrouters on the wide area network can only follow the arrangement of ICANN. If you really want the world to admit it, you can change the route table step by step from the vro of the local telecom, if you can.