Help Center/ NAT Gateway/ User Guide (Kuala Lumpur Region)/ Getting Started/ Using SNAT to Access the Internet/ Step 3: Add an SNAT Rule
Updated on 2022-08-08 GMT+08:00
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Step 3: Add an SNAT Rule

Scenarios

After a NAT gateway is created, add SNAT rules. With an SNAT rule, your servers in a specified subnet can access the Internet by sharing the same EIP.

Each SNAT rule is configured for one subnet or CIDR block. If there are multiple subnets or CIDR blocks in a VPC, you can create several SNAT rules to allow multiple servers to share EIPs.

Prerequisites

A NAT gateway has been created.

Procedure

  1. Log in to the management console.
  2. Under Network, choose NAT Gateway.
  3. On the displayed page, click the name of the NAT gateway for which you want to add the SNAT rule.
  4. On the SNAT Rules tab, click Add SNAT Rule.
  5. Configure the parameters as prompted. Table 1 describes the parameters.
    Table 1 Parameter descriptions

    Parameter

    Condition

    Description

    Scenario

    N/A

    Select VPC if your servers in a VPC will use the SNAT rule to access the Internet.

    Different servers in a VPC can share the same EIP to access the Internet.

    Type

    This parameter is available only when you select VPC for Scenario.

    You can set it to Subnet or Custom based on service requirements.

    Select Subnet if all servers in a VPC subnet need to access the Internet through the SNAT rule.

    Select Custom if only specific servers in a VPC subnet need to access the Internet through the SNAT rule.

    Subnet

    This parameter is available only when you select VPC for Scenario, and Subnet for Type.

    The subnet in which servers can access the Internet through the SNAT rule.

    CIDR Block

    This parameter is available only when you select VPC for Scenario, and Custom for Type.

    The CIDR block is a subset of the NAT gateway's VPC subnets. Servers whose IP addresses in the custom CIDR block can access the Internet through the SNAT rule.

    EIP

    N/A

    The EIP used for accessing the Internet.

    You can select an EIP that either is not bound to any resource, has been bound to a DNAT rule with Port Type set to Specific port of the current NAT gateway, or has been bound to an SNAT rule of the current NAT gateway.

    Monitoring

    N/A

    Alarm rules are created in Cloud Eye.

    The alarm rules help you monitor your SNAT connections and keep you informed of any changes in a timely manner.

    Description

    N/A

    Supplementary information about the SNAT rule. The description can contain up to 255 characters.
  6. Click OK.

    You can add multiple SNAT rules for a NAT gateway to suite your service requirements.