Elastic cloud servers may require modification of their private IP addresses due to network planning adjustments, changes in business needs, or architecture optimizations. Major cloud service providers offer corresponding solutions, which differ slightly in implementation procedures but share the same core principles. The following shares basic operations, which are largely similar. If you have any questions about IP usage in the Jtti.cc backend, please contact the official technical support!
The cloud server instance must be powered off before modifying its private IP address; this is a basic prerequisite required by most cloud service providers. Huawei Cloud documentation explicitly states that modifying the private IP address of the primary elastic network interface must be performed in a "power off" state.
If the instance's network interface is bound to a virtual IP or DNAT rule, it must be unbound before modifying the private IP. Also, if the network interface is configured with an IPv6 address, the private IP address, including both IPv4 and IPv6 addresses, cannot be modified.
For instances acting as backend servers for elastic load balancers, the instance must be removed from the backend server group before modifying its private IP address. The IP address must then be modified and rebound. In some cases, changing the primary IP address of the main network interface card (NIC) will cause the associated cloud server to automatically restart, while the primary IP address of the secondary NIC cannot be changed.
After logging into the cloud server management console, first locate the target instance whose private IP address needs to be modified in the instance list. Click the instance name to enter the details page and select the "Elastic NIC" tab.
In the Elastic NIC interface, locate the primary NIC and click the "Modify Private IP" button in the row containing the primary NIC. In the platform's operation interface, this function is labeled "Modify Primary IP".
A configuration window will pop up, where you can modify the "Subnet" and "Private IP Address" of the primary elastic NIC. The subnet option is limited to subnets within the current VPC and cannot be changed across VPCs. The private IP address can be manually specified or automatically assigned by the system: if the "Private IP Address" field is not filled in, the system will automatically assign a new address; when manually filling it in, ensure that the address is an available IP within the current subnet's CIDR range.
After confirming that the configuration information is correct, click "OK" to submit the changes. The Huawei Cloud platform will immediately execute the modification operation, and the platform will trigger an instance restart to make the new IP address take effect. When it's necessary to change the subnet of an instance, the platform supports this through the "Change Instance Subnet" operation. This operation will simultaneously change the instance's private IP address, as IP addresses are bound to subnets.
Switching to a Virtual Private Cloud (VPC) is a more complex network change operation. The documentation states that before migration, you need to manually unbind the internal and external network load balancers and elastic network interfaces (NICs), and release the secondary IP address of the primary NIC. After migration, you need to rebind them. This operation will change the instance subnet, private IP address, MAC address, and the operating system's internal NIC name.
Switching from the basic network to a VPC network is irreversible. After the switch, the cloud server instance will be unable to communicate with other cloud services in the basic network, which must be fully considered in the business architecture design.
Modifying the private IP address will cause a temporary network connection interruption. Some cloud platforms explicitly state that modifying the primary IP address of the primary NIC will cause the instance to automatically restart, and the instance also needs to restart during the VPC switch.
Regarding business continuity, the impact of IP address changes on related services needs to be assessed. If the instance IP address is hardcoded in other application configurations, these configurations must be updated synchronously. Simultaneously, check if security group rules need adjustment to ensure the new IP address will not trigger access restrictions.
After the operation, integrity verification is required. Check if the instance is running normally and confirm that intranet access and remote login functions have been restored. If necessary, conduct comprehensive testing of application services that depend on this instance to ensure business functions are unaffected.
Documentation and knowledge management are crucial. After modifying the IP address, promptly update the network topology diagram and IP address allocation table in internal documents to maintain the accuracy and consistency of infrastructure information, providing a reliable basis for subsequent operation and maintenance work.
Modifying the private IP address of an Elastic Cloud Server is a routine operation in cloud resource management. Following the correct operating procedures and precautions can effectively reduce the risk of business interruption and ensure the smooth implementation of network changes. While the specific operation interfaces of different cloud service providers may vary slightly, the core principles and precautions are basically the same. Mastering these basic principles will allow you to adapt to the operating environments of different cloud platforms.
