Public IP address and internal IP address are two common types of IP addresses in network communication, and they have obvious differences. A public IP (also known as an Internet IP) is an IP address that can be publicly accessed, while an Intranet IP (also known as a LAN IP) is an IP address that is used in a private network. This section describes the differences between public IP addresses and Intranet IP addresses, and provides methods to distinguish public IP addresses from Intranet IP addresses.
First, let's take a brief look at public IP and Intranet IP:
Public IP address: A public IP address is a publicly accessible IP address that uniquely identifies and locates devices on the Internet. Usually, when we talk about IP addresses, we are referring to public IP addresses. Each computer connected to the Internet is assigned a separate public IP address, which can be used to interact and communicate with other computers on the Internet.
Public IP addresses have the following features and functions:
Uniqueness: Public IP addresses are unique worldwide, and each device needs to have an independent public IP address in order to communicate with other devices over the Internet.
Public access: A public IP address can be used by other devices and users to communicate and interact with the device, for example, accessing websites and downloading files.
External services: The public IP address is used to establish external services, such as website construction, remote access, and video conferencing, so that other network users can access and use the device.
Global reachability: Since public IP addresses are globally reachable, devices can communicate with other devices located in any geographic location to achieve global connectivity.
Internet Identity: Public IP addresses are used to identify and locate devices on the Internet, which is the basis of Internet communication.
Note that due to the limited IPv4 address resources, the allocation of public IP addresses is limited and managed. Each region or organization can obtain only a certain number of public IP addresses. With the development of the Internet and the increase of devices, IPv6 addresses were introduced to provide more IP address space to meet the growing demand.
In short, a public IP address is a publicly accessible IP address used to uniquely identify and locate a device on the Internet so that the device can communicate and interact with other devices worldwide. It is the foundation of Internet communication, supporting various online services and the realization of global interconnection.
Intranet IP: Some businesses or schools often apply for a fixed IP address, and then IP sharing allows the entire organization's computers to access the Internet. The IP address used by the computers in these organizations is the Intranet IP. It should be noted that computers on the Intranet can send connection requests to other computers on the Internet, but other computers on the Internet cannot directly send connection requests to computers on the Intranet.
The differences between public IP addresses and Intranet IP addresses are as follows:
The access modes are different: A public IP address connects to a non-reserved address on the Internet through the public network, whereas an Intranet IP address is an IP address on the local area network (LAN) and can communicate with the public network through network address translation (NAT).
Different features: Public IP addresses are assigned by the International Internet Network Information Center (InterNIC) to registered institutions or organizations that apply to InterNIC. Intranet IP addresses translate public IP addresses into a large number of Intranet IP addresses to save the number of registered IP addresses that can be assigned, so that a large number of devices in an area can connect to the network at the same time.
Advantages: The public IP address is open, and users can access the Internet directly through the public IP address. However, users using the internal IP address must use NAT to translate the IP address into an available IP address on the public network.
How to distinguish between public IP addresses and internal IP addresses?
On the computer side, click "Start" - "Run" - type "CMD" and enter (to open the command window). Then type "ipconfig" and press enter. Four lines of data will be returned.
The first behavior uses the DNS (domain name resolution server address), the second behavior uses the local IP address, the third behavior uses the subnet mask, and the fourth behavior uses the gateway.
To distinguish the Intranet from the extranet, observe the four groups of numbers separated by "." on the right of the second row. If 192.168... 10... Or 127.0... If yes, an Intranet IP address is used. If the IP address starts with a number other than the preceding three groups (for example, 202.96.64.), the IP address is a public IP address.