Help Center/ Elastic Cloud Server/ Getting Started/
Updated on 2024-09-06 GMT+08:00
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Step 2: Configure Network

Network Settings

  1. Set Network by selecting an available VPC and subnet from the drop-down list and specifying a private IP address assignment mode.

    VPC provides a dedicated network for your ECS. A VPC can contain subnets for further isolation. You can configure security groups per subnet to control access to cloud resources.

    You can select an existing VPC or create a new one.

    For more information about VPC, see Virtual Private Cloud.

    • Ensure that DHCP is enabled in the VPC which the ECS belongs to.
    • When you use VPC for the first time, the system automatically creates a VPC for you, including the security group and NIC.
  2. (Optional) Add an extension NIC. You can add multiple extension NICs to an ECS and specify IP addresses for them (including primary NICs).

    If you specify an IP address for a NIC when creating multiple ECSs in a batch:

    • This IP address serves as the start IP address.
    • Ensure that the IP addresses required by the NICs are within the subnet, consecutive, and available.
    • The subnet with the specified IP address cannot overlap with other subnets.
    • IPv6 not required/Automatically-assigned IPv6 address: This parameter is available only if the ECS is of specific flavors and in a VPC with IPv6 enabled. For details about how to enable IPv6 on a subnet, see IPv4 and IPv6 Dual-Stack Network. For details about how to check whether an ECS supports IPv4/IPv6 dual stack, see "Constraints" in Dynamically Assigning IPv6 Addresses.

      By default, the system assigns IPv4 addresses. If you select Automatically-assigned IPv6 address, the system assigns IPv6 addresses. In a VPC, an ECS uses an IPv6 address to access the dual-stack intranet. To access the Internet, you must enable IPv6 Bandwidth and select a shared bandwidth. Then, the ECS accesses the IPv6 Internet through the IPv6 address.

      After purchasing an ECS, enable IPv6 so that the ECS dynamically obtains an IPv6 address. For details, see Dynamically Assigning IPv6 Addresses.
      • IPv6 can be enabled only during ECS creation, and the configuration cannot be modified after the ECS is created. If IPv6 Bandwidth is not enabled when you create an ECS, you can enable it after the ECS is created.
      • Dedicated bandwidth is not supported.
    • Source/Destination Check

      When this function is enabled, source IP addresses in the outbound packets will be checked. If the IP addresses are incorrect, the packets will not be sent out. This function helps prevent spoofing packet attacks and improve security. By default, Source/Destination Check is enabled.

      The source/destination check settings apply only to the NICs created with the ECS.

  3. Set Security Group by selecting an available security group from the drop-down list or creating a new one.

    A security group controls ECS access within or between security groups by defining access rules. This enhances ECS security.

    When creating an ECS, you can select multiple (recommended not more than five) security groups. In such a case, the access rules of all the selected security groups apply on the ECS.

    Before initializing an ECS, ensure that the security group rules for the outbound direction meet the following requirements:

    • Protocol: TCP
    • Port: 80
    • Source: 169.254.0.0/16

    If you use the default security group rules for the outbound direction, the preceding requirements are met, and the ECS can be initialized. The default security group rules for the outbound direction are as follows:

    • Protocol: ANY
    • Port: ANY
    • Remote End: 0.0.0.0/16
  4. Set EIP.

    An EIP is a static public IP address bound to an ECS in a VPC. Using the EIP, the ECS can provide services externally.

    The following options are provided:

    • Auto assign

      The system automatically assigns an EIP for the ECS. The EIP provides a dedicated bandwidth that is configurable.

    • Use existing

      An existing EIP is assigned for the ECS. When using an existing EIP, you are not allowed to create ECSs in a batch.

    • Not required

      Without an EIP, the ECS cannot access the Internet and is used in the private network or cluster only.

    For a yearly/monthly ECS, Auto assign is unavailable to EIP. If an EIP is required, bind an existing EIP to the ECS. Alternatively, purchase an EIP that is billed in pay-per-use payment and then bind the EIP to the ECS.

  5. Set EIP Type.
    • Dynamic BGP provides automatic failover and load balancing capabilities and makes better routing decisions based on optimal paths when a network connection fails.
    • Static BGP offers routing control and protects against route flapping, but cannot choose an optimal path in real time when a network connection fails.
  6. Set Billed By.

    This parameter is mandatory when EIP is set to Auto assign. If you select Bandwidth or Traffic, the system will allocate a dedicated bandwidth for you, and the bandwidth is dedicated for one EIP.

    • Bandwidth: You will be billed based on the duration for which the bandwidth is used.
    • Traffic: You will be billed based on the total traffic usage irrespective of the duration for which the bandwidth is used.
    • Shared bandwidth: The bandwidth can be used by multiple EIPs and you will be billed based on the shared bandwidth.
      • A bandwidth can be shared among a limited number of EIPs. If the number of EIPs cannot meet service requirements, switch to a higher shared bandwidth or apply for expanding the EIP quota of the existing bandwidth.
      • EIPs that are billed yearly/monthly do not support shared bandwidths.
      • When a shared bandwidth that is billed yearly/monthly expires, the system automatically deletes the bandwidth configuration and creates a dedicated bandwidth billed by traffic for the EIPs sharing the deleted bandwidth configuration.
  7. Set Bandwidth Size.

    Select the bandwidth based on service requirements. The unit is Mbit/s.

  8. Click Next: Configure Advanced Settings.