What is the difference between private IP address and public IP address?
1. Different access methods
Public IP: It is an IP address assigned by an Internet service provider. It can communicate directly on the Internet. When a device is connected to a public IP, it can be directly accessed by other devices around the world. For example, a server with a public IP can receive client requests from all over the world.
Private IP: It is mainly used in internal networks and is assigned by routers or network administrators in a local area network. It needs to be converted to a public IP through network address translation technology to interact with the external network. Devices connected to private IP can only communicate within the local area network and cannot be directly accessed by external networks.
2. Different characteristics
Public IP has uniqueness (unique within the global Internet); publicness (publicly visible); dynamic + static (dynamic public IP is reallocated every time it is connected to the Internet, and static public IP is fixed and unchanged, usually requiring payment).
Private IP has the characteristics of reusability (different LANs can use the same private IP address range); non-publicity (not visible to the external network, only available in the local LAN); fixedness (manually assigned by the network administrator or automatically assigned in the LAN through DHCP).
3. Different advantages
Public IP: ① Global communication: The device can communicate directly with other devices around the world, which is very important for servers that provide external services. ② Direct access: External devices can directly access the device with the address through the public IP address. ③ Stability (static public IP): Ensure that the device IP address does not change frequently, which is convenient for access and management.
Private IP: ① Security: It is invisible to the external network, reducing the risk of being attacked, and the internal network structure and device information can be hidden through network address translation. ② Convenient internal management: It is convenient for network administrators to manage devices, allocate IP addresses and configure networks. ③ Save public IP resources: It can be reused in the internal network, reducing the demand for public IP addresses.
