IPv4 and IPv6

Static and dynamic IP in IPv4 environment： In the IPv4 environment, IP address allocation methods are mainly divided into static and dynamic. Static IP addresses are manually assigned by network administrators and do not depend on DHCP servers, so devices using static IP will not initiate DHCP requests. This method provides accurate control of network devices, avoids IP address conflicts, and provides higher stability and security because devices always use the same IP address.  Static IP allows the network administrator to precisely control the IP address of each device to ensure that each device in the network has a unique and fixed address. Since the device will not lose its IP address due to the expiration of the DHCP lease, the device using static IP can maintain a continuous network connection. Static IP configuration reduces the security risk caused by automatic IP allocation, because the IP address of each device is known and fixed in advance. However, the manual configuration of static IP addresses may increase the complexity of network management, especially in large networks. In addition, with the increasing shortage of IPv4 address space, static allocation may cause a waste of address resources.  Trend of IP address allocation in IPv6 environment： The trend of IP address allocation in IPv6 environment is developing towards more automation and scale. IPv6 provides almost unlimited address space, which enables each device to have a unique global unicast address. In IPv6, address allocation mainly depends on two mechanisms: DHCPv6 and SLAAC (Stateless Address Automatic Configuration). DHCPv6: This is the IPv6 version of the DHCP protocol, which allows devices in the network to request IPv6 addresses and other configuration information from the DHCPv6 server.  DHCPv6 supports centralized management and can provide complete network configuration for devices, including address assignment and update.  SLAAC: This is a stateless address automatic configuration method, which allows devices to automatically build IPv6 addresses when connecting to the network. SLAAC generates IPv6 address through the Router Advertisement message sent by the router and the MAC address of the device, which reduces the dependence on the central server. These address allocation mechanisms of IPv6 make the network configuration more flexible and efficient, and also provide convenience for the network expansion and maintenance. With the popularization of IPv6, it is expected that more and more devices in the future network will adopt these automatic address allocation technologies. In addition, the address allocation trend of IPv6 also includes the enhancement of privacy and security, such as protecting users' privacy through temporary addresses and improving the security of data transmission through built-in IPsec support.