Help Center/ NAT Gateway/ User Guide (Kuala Lumpur Region)/ Getting Started/ Using SNAT and DNAT Rules to Allow On-premises Servers to Communicate Over the Internet/ Step 4: Add an SNAT Rule
Updated on 2022-08-16 GMT+08:00
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Step 4: Add an SNAT Rule

Scenarios

After a NAT gateway is created, you can add SNAT rules for it. With SNAT rules, servers that are connected to a VPC using Direct Connect can access the Internet by sharing an EIP.

An SNAT rule is configured for one CIDR block. If servers that are connected to a VPC using Direct Connect are in multiple CIDR blocks, you can create several SNAT rules to make the servers share one or more EIPs.

Prerequisites

A NAT gateway has been created.

Procedure

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

    Parameter

    Description

    Scenario

    Select Direct Connect if servers in your data center need to access the Internet.

    The servers in your data center that are connected to a VPC through Direct Connect or VPN can access the Internet through the SNAT rule.

    CIDR Block

    On-premises servers whose IP address in this CIDR block can access the Internet through the SNAT rule.

    EIP

    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

    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

    Supplementary information about the SNAT rule. The description can contain up to 255 characters.
  5. Click OK.
  6. View details in the SNAT rule list. If Status is Running, the rule has been added.

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