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    Virtual Private Cloud:Create and manage a VPC

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    Virtual Private Cloud:Create and manage a VPC

    Last Updated:Oct 26, 2023

    A virtual private cloud (VPC) is a private network in the cloud. You can manage your VPC based on your business requirements. For example, you can specify CIDR blocks, and configure route tables and gateways for your VPC. You can also add secondary CIDR blocks to a VPC. This topic describes how to create and manage a VPC.

    Operations

    Create a VPC and a vSwitch

    Make a networking plan before you create a VPC and a vSwitch. For more information, see Plan networks.

    1. Log on to the VPC console.

    2. In the top navigation bar, select the region where you want to create a VPC and a vSwitch.

      Note

      The VPC and the cloud resources that you want to deploy in the VPC must belong to the same region.

    3. On the VPC page, click Create VPC.

    4. On the Create VPC page, set the following parameters and click OK.

      Parameter

      Description

      VPC

      Region

      Displays the region where you want to create the VPC.

      Name

      Enter a name for the VPC.

      IPv4 CIDR Block

      Enter the primary IPv4 CIDR block of the VPC.

      • You can specify one of the following CIDR blocks or their subsets as the primary IPv4 CIDR block of the VPC: 192.168.0.0/16, 172.16.0.0/12, and 10.0.0.0/8. These CIDR blocks are standard private CIDR blocks as defined by Request for Comments (RFC) documents. The subnet mask must be 8 to 28 bits in length. Example: 192.168.0.0/24.

      • You can also use a custom CIDR block other than 100.64.0.0/10, 224.0.0.0/4, 127.0.0.0/8, 169.254.0.0/16, and their subnets as the primary IPv4 CIDR block of the VPC.

      • In scenarios where multiple VPCs are used or in hybrid cloud scenarios where data centers and VPCs are used, we recommend that you use subsets of standard RFC CIDR blocks as VPC CIDR blocks with subnet masks no more than 16 bits in length. Make sure that the CIDR blocks of the VPCs do not overlap in both scenarios. In addition, the CIDR blocks of the VPCs cannot overlap with those of the data centers in hybrid cloud scenarios.

      Note

      After you create a VPC, you cannot change its primary IPv4 CIDR block. However, you can add a secondary IPv4 CIDR block to the VPC. For more information, see Add a secondary CIDR block.

        IPv6 CIDR Block

        Specify whether to assign an IPv6 CIDR block to the VPC. In this example, Assign (Default) is selected.

        If you set this parameter to Assign, the system automatically creates an IPv6 gateway of Free Edition for this VPC, and assigns an IPv6 CIDR block with the subnet mask /56, such as 2408:4005:3c5:6e00::/56. By default, IPv6 addresses are used only for communication within private networks. If you want to use an IPv6 address to access the Internet or provide services for IPv6 clients over the Internet, you must purchase Internet bandwidth for the IPv6 address. For more information, see Enable and manage IPv6 Internet bandwidth.

        Note

        • Only the following regions support IPv6 CIDR blocks: China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Hangzhou), China (Shanghai), China (Fuzhou - Local Region), China (Shenzhen), China (Heyuan), China (Guangzhou), China (Chengdu), China (Hong Kong), Philippines (Manila), Singapore, Japan (Tokyo), Indonesia (Jakarta), US (Virginia), and Germany (Frankfurt)

        • After you create a VPC, you cannot change its IPv6 CIDR block. However, you can add a secondary IPv6 CIDR block to the VPC. For more information, see Add a secondary CIDR block.

        Description

        Enter a description for the VPC.

        Resource Group

        Select the resource group to which the VPC belongs.

        Tag Key

        Select or enter a tag key.

        You can specify at most 20 tag keys. A tag key can be up to 64 characters in length. It cannot start with aliyun or acs:, and cannot contain http:// or https://.

        Tag Value

        Select or enter a tag value.

        You can specify at most 20 tag values. A tag value can be at most 128 characters in length. It cannot start with aliyun or acs:, and cannot contain http:// or https://.

        vSwitch

        Name

        Enter a name for the vSwitch.

        Zone

        In the drop-down list, select a zone for the vSwitch. In the same VPC, vSwitches in different zones can communicate with each other.

        The drop-down list shows whether Elastic Compute Service (ECS) instances, ApsaraDB RDS instances, internal-facing Classic Load Balancer (CLB) instances, and internal-facing Application Load Balancer (ALB) instances are supported in each zone. The supported cloud resources vary based on the zone and the creation time of the cloud resources. The instances provided in this topic are for reference only. The actual instances on the buy page shall prevail.

        IPv4 CIDR Block

        Enter an IPv4 CIDR block for the vSwitch. When you specify a CIDR block for the vSwitch, take note of the following limits:

        • The CIDR block of a vSwitch must be a subset of the CIDR block of the VPC to which the vSwitch belongs.

          For example, if the CIDR block of a VPC is 192.168.0.0/16, the CIDR block of a vSwitch in the VPC can range from 192.168.0.0/17 to 192.168.0.0/29.

        • The first IP address and the last three IP addresses of a vSwitch CIDR block are reserved.

          For example, if a vSwitch CIDR block is 192.168.1.0/24, the IP addresses 192.168.1.0, 192.168.1.253, 192.168.1.254, and 192.168.1.255 are reserved.

        • If a vSwitch is required to communicate with vSwitches in other VPCs or with data centers, make sure that the CIDR block of the vSwitch does not overlap with the destination CIDR blocks.

        Note

        After you create the vSwitch, you cannot change its CIDR block.

        IPv6 CIDR Block

        Specify whether to enable IPv6 for the vSwitch. If you enable IPv6, you must specify an IPv6 CIDR block for the vSwitch.

        Note

        • If your VPC is assigned an IPv6 CIDR block, you must configure the IPv6 CIDR block of the vSwitch.

        • If your VPC is not assigned an IPv6 CIDR block, you do not need to configure the IPv6 CIDR block of the vSwitch.

        In this example, Enable is selected.

        By default, the subnet mask of the IPv6 CIDR block of a vSwitch is /64. You can enter a decimal number from 0 to 255 to define the last 8 bits of the IPv6 CIDR block.

        For example, if the IPv6 CIDR block of the VPC is 2408:4005:3c5:6e00::/56, you can enter 255 (ff in hexadecimal format) for the IPv6 CIDR block of the vSwitch. In this case, the IPv6 CIDR block of the vSwitch is 2408:4005:3c5:6eff::/64.

      • (Optional): If you need to add more vSwitches for the VPC, click Add below the vSwitch list and set the parameters.

        You can add at most 10 vSwitches in each VPC.

      • Click OK.

      View a VPC

      1. Log on to the VPC console.

      2. In the top navigation bar, select the region where the VPC is created.

      3. On the VPCs page, click the ID of the VPC that you want to manage.查看VPC

      4. Then, you can view the VPC Details, vRouter Basic Information, Resource Management, and CIDR Block Management of the VPC.

        • You can click the Advanced Features tab to view the advanced features of the VPC.

          The advanced features that are supported by the VPC are displayed. For more information, see Advanced VPC features.

        • Click the Authorize Cross Account Attach CEN tab to grant permissions to a Cloud Enterprise Network (CEN) instance of another Alibaba Cloud account. This way, you can attach the VPC to the CEN instance. For more information, see Grant permissions to an Alibaba Cloud account.

        • Click the Cross-Account VBR Authorization tab to grant permissions to a VBR that belongs to another Alibaba Cloud account. After the permissions are granted, the VPC can connect to the VBR.

        • Click the Network Topology tab to view the topology of the VPC.

      Modify the basic information about a VPC

      You can modify the name and description of a VPC.

      1. Log on to the VPC console.

      2. In the top navigation bar, select the region where the VPC is created.

      3. On the VPCs page, click the ID of the VPC that you want to manage.

      4. In the VPC Details section, click Edit on the right side of Name. In the dialog box that appears, modify the name and click OK.

      5. Click Edit on the right side of Description. In the dialog box that appears, modify the description and click OK.

      Add a secondary CIDR block

      Limits

      • When you create a VPC, the IPv4 CIDR block that you specified is the primary CIDR block. After the VPC is created, you cannot modify the primary IPv4 CIDR block of the VPC. However, you can add a secondary IPv4 CIDR block to the VPC. After you add a secondary IPv4 CIDR block to the VPC, both the primary and secondary IPv4 CIDR blocks are in effect.

        You can add at most five secondary IPv4 CIDR blocks to a VPC and at most three secondary IPv6 CIDR blocks to a VPC that has IPv6 enabled.

      • You can create a vSwitch with the primary IPv4 CIDR block or a secondary CIDR block of a VPC. However, the CIDR block of a vSwitch must belong to only one CIDR block of the VPC. Whether you create a vSwitch with the primary IPv4 CIDR block or a secondary CIDR block, the system automatically adds a route to a route table of the VPC. The destination CIDR block of the route is the CIDR block of the vSwitch. The CIDR block of a vSwitch cannot be the same as or larger than the destination CIDR block of a route in a route table of the VPC to which the vSwitch belongs.

        For example, 172.16.0.0/12 is added to a VPC as a secondary IPv4 CIDR block and a CEN route exists in a route table of the VPC. Overlapping routing is enabled for CEN and the destination CIDR block of the CEN route is 172.16.0.0/24. In this case, you cannot create a vSwitch with 172.16.0.0/24 or a larger CIDR block. However, you can create a vSwitch with 172.16.0.0/25 or a smaller CIDR block.

      Prerequisites

      Before you add a secondary IPv4 CIDR block to a VPC, make sure that a VPC is created. If you want to add a secondary IPv6 CIDR block to a VPC, you must enable IPv6 for the VPC. If you want to create a vSwitch with a secondary IPv6 CIDR block, you must enable IPv6 for the vSwitch.

      1. Log on to the VPC console.

      2. In the top navigation bar, select the region where the VPC is created.

      3. On the VPC page, find the VPC that you want to manage, and click the ID of the VPC.

      4. On the VPC Details page, click the CIDR Block Management tab and perform the following steps to add a secondary CIDR block to the VPC.

        • Add a secondary IPv4 CIDR block

          1. Click the IPv4 CIDR Block tab, and click Add Secondary IPv4 CIDR Block.

          2. In the Add Secondary CIDR Block dialog box, set the following parameters and click OK.

            Parameter

            Description

            VPC

            The VPC to which you want to add a secondary IPv4 CIDR block is displayed.

            Secondary CIDR Block

            Select a method to add a secondary IPv4 CIDR block:

            • Default CIDR Block: Uses 192.168.0.0/16, 172.16.0.0/12, or 10.0.0.0/8 as the secondary CIDR block.

            • Custom CIDR Block: Uses 100.64.0.0/10, 224.0.0.0/4, 127.0.0.0/8, or 169.254.0.0/16, or their subnet as the secondary CIDR block.

            When you add a secondary IPv4 CIDR block, take note of the following limits:

            • The CIDR block cannot start with 0. The subnet mask must be 8 to 28 bits in length.

            • The secondary IPv4 CIDR block cannot overlap with the primary IPv4 CIDR block or an existing secondary IPv4 CIDR block.

              For example, if the primary IPv4 CIDR block of a VPC is 192.168.0.0/16, you cannot specify one of the following CIDR blocks as the secondary IPv4 CIDR block:

              • 192.168.0.0/16.

              • A CIDR block that is larger than 192.168.0.0/16, for example, 192.168.0.0/8.

              • A CIDR block smaller than 192.168.0.0/16, for example, 192.168.0.0/24.

        • Add a secondary IPv6 CIDR block

          1. Click the IPV6 CIDR Block tab and click Add IPv6 CIDR Block.

          2. In the Add IPv6 CIDR Block dialog box, set the following parameters and click OK.

            Parameter

            Description

            IPv6 CIDR Block Type

            Select the type of IPv6 CIDR block. You can select only Assign (Default), which specifies a secondary IPv6 CIDR block.

            IPv6 CIDR Block

            The assigned secondary IPv6 CIDR block is displayed.

      Delete a secondary CIDR block

      You can delete a secondary CIDR block. However, you cannot delete the primary IPv4 CIDR block of a VPC.

      Before you delete a secondary CIDR block, make sure that the vSwitches created within the secondary CIDR block are deleted. For more information, see Delete a vSwitch.

      1. Log on to the VPC console.

      2. In the top navigation bar, select the region where the VPC is created.

      3. On the VPCs page, find the VPC that you want to manage, and click the ID of the VPC.

      4. On the VPC Details page, click the CIDR Block Management tab.

      5. On the CIDR Block Management tab, perform the following steps to delete a secondary CIDR block:

        • Delete a secondary IPv4 CIDR block

          1. On the IPv4 CIDR Block tab, find the secondary IPv4 CIDR block that you want to delete and click Delete in the Actions column.

          2. In the message that appears, click OK.

        • Delete a secondary IPv6 CIDR block

          1. On the IPv6 CIDR Block tab, find the secondary IPv6 CIDR block that you want to delete and click Delete in the Actions column.

          2. In the message that appears, click OK.

      Delete a VPC

      If you no longer use a VPC, you can delete it. The vRouters and route tables associated with the VPC are also deleted.

      • Natural deletion: Make sure that the VPC is not associated with vSwitches, IPv6 gateways, security groups, custom route tables, access control lists (ACLs), DHCP sets, or CEN instances. If the VPC is associated with a resource, release the resource first.

      • Forceful deletion: The VPC can be forcefully deleted if it is associated only with the following resources. The associated resources are also deleted.

        • vSwitches whose private IP addresses are available.

        • Route tables that do not contain custom routes or contain only routes that point to IPv4 or IPv6 gateways.

        • Network ACLs.

        • IPv4 gateways.

        • IPv6 gateways.

        If the VPC is associated with other resources, the VPC cannot be forcefully deleted. You must release the associated resources first.

      1. Log on to the VPC console.

      2. In the top navigation bar, select the region where the VPC is created.

      3. On the VPCs page, find the VPC that you want to delete and click Delete in the Actions column.

      4. In the Delete VPC dialog box, select or clear Forcefully Delete, and click OK.

      What to do next

      Disable IPv6 for a VPC

      If a VPC that has IPv6 enabled no longer requires IPv6, you can disable IPv6 for the VPC. Before you disable IPv6 for a VPC, you must disable IPv6 for all the vSwitches in the VPC, and delete the IPv6 gateway of the VPC.

      1. Log on to the VPC console.

      2. In the top navigation bar, select the region where the VPC is created.

      3. On the VPCs page, click the ID of the VPC for which you want to disable IPv6.

      4. Click the Resources tab. In the VPC Resources section, click the number below the VSwitch parameter.

      5. On the vSwitch page, view the IPv6 CIDR blocks of vSwitches in the IPv6 CIDR Block column.

      6. (Optional): If IPv6 is enabled for the vSwitch, click Disable IPv6 CIDR Block in the IPv6 CIDR Block column.

        You must disable IPv6 for all the vSwitches that have IPv6 enabled in the VPC.

      7. (Optional): In the left-side navigation pane, choose Access to Internet > IPv6 Gateway.

      8. (Optional): On the IPv6 Gateway page, check for IPv6 gateways in the VPC for which you want to disable IPv6 CIDR blocks.

        • If such an IPv6 gateway exists in the VPC for which you want to disable IPv6, click Delete in the Actions column. In the message that appears, click OK.

        • If no IPv6 gateway exists in the VPC for which you want to disable IPv6, skip this step.

      9. Return to the VPCs page, find the VPC for which you want to disable IPv6, and then click Disable IPv6 CIDR Block in the IPv6 CIDR Block column. In the message that appears, click OK.

      References