What are dynamic IP addresses, internal IP addresses, and external IP addresses? We observed that in fact, in China, the demand for dynamic proxy IP is the most vigorous in the world. As we all know, China is a country with a serious shortage of IP addresses. Therefore, our dial-up broadband has always been dynamic without fixed IP. Is when you use, the operator will allocate an IP address for you to use, when you go offline, the IP address may be allocated to other people to use, if the IP address is compared to the real number of the house, then your house is not fixed number, this is also a very magic thing.
After more excessive is the emergence of Intranet in many cities, and all of our secondary broadband are Intranet, Intranet more and more appear in our life, so we just derived, Intranet penetration and so on.
Some friends ask, what is the internal network, today tomato accelerate www.fanqieip.net/ to say with everyone.
What is an external IP address
Our Internet is just like a broad street, all kinds of websites on the Internet, providing services, just like all kinds of bottom business on the side of the street.
We all know that the stores are open directly on the street side, their doors are directly facing the street, the purpose is to facilitate customers in and out of the shopping, consumption.
Street numbers 1,2,3… Just like an extranet, when we want to go to a place, we directly press the number of the house, we can find it, this is the so-called extranet IP address.
For example, McDonald’s on the left, 7-Eleven, etc.
What is dynamic IP address
More and more people come to this road, some shopping, some doing small business, but there are too many people and there are not so many places, how to do?
Due to the characteristics of some people liquidity, in order to facilitate management, we will leave the right place 2, 4 out, tell some carts do small business, you can only in 2, 4 these two places, other places are not allowed to go, first come, first served, no fixed booth.
(This is called dynamic, first dial, first serve, not fixed).
After doing too many small businesses, 2 booths are not enough, often come late to find there is no booth, go back. In the early dialing period, you could not dial the number because there was no address assigned to you.
When a person closed his stall, a vacant stall, just this is another stall, so he followed this stall, continue to do business.
(When a person goes offline, the IP address is freed up and given to a new dial-up user, allowing the IP address to be reused), and so on.
What is an Intranet IP address
But after the economy developed, want to do business is too much, but there is only one booth 6, how to do?
For the sake of economic development, let’s build office buildings, let’s all work in the office buildings, each person has a room, the numbers are 101, 102, 103… Some house numbers are called Intranet IP addresses.
Disadvantages of Intranet IP addresses
As you know, most businesses wait for people to come to their door, rather than actively go to the street to attract customers, so some Intranet IP business started advertising messages, xiaobian 101, xiaobian is a beauty, another xiaobian 102, xiaobian is a loan, you come.
(Let’s tell our friends about the Intranet and let them visit), but no one came for a long time, what’s the matter?
In fact, many people who read the advertisement were interested, but they could not find 101 or 102 on the street for a long time, so they had to go home.
When we access an Intranet directly, we cannot find the address, so we lose the packet. The biggest disadvantage of the Intranet is that you cannot find the address and access it directly.
What is port forwarding
Office people a look, this is not ah, business or to do, how to do? So hire a front office and tell her, if someone asks you where the barbershop is, you tell them it’s on 101. (Starts to configure port forwarding.)
So again advertising information, xiaobian business opened, in the backbone network 6 barber shop ah!
IP address: Port
Backbone 6: Barbershop
201.113.233.111:80
So people went to no.6, said xiaobian to go to the barber shop, the lobby sister said, go to room 101. (Router ports are forwarded to corresponding ports).
If port forwarding is not set up, it is like a person gets to number 6 and shouts, “Xiaobian wants to go to the barber’s, xiaobian wants to go to the barber’s, xiaobian wants to go to the barber’s, and no one pays attention to him, so he goes home.”
What is blocked port 80
Slowly, people know that barbershops make money, as long as the future to build an office building to open a barbershop (Web server).
Since the original barbershop was in Room 101, it was assumed that room 101 was the barbershop, and no further explanation was required. (Port 80 is the default web access port.)
But because some people play tricks in the barbershop, the administrator a look, this is not this is not messed up?
So the next order said, from now on all office building room 101, do not open, want to open must examine.
(Mandatory closure of port 80, audit system), business in other rooms is normal.
The above is about an example to explain to you what is dynamic IP, internal IP, and external IP popular explanation, perhaps not accurate, but I hope to let the white understand.