Step 3: Add a DNAT Rule

Scenarios

After a NAT gateway is created, you can add DNAT rules to allow servers in your VPC to provide services accessible from the Internet.

You can configure a DNAT rule for each port of a server. If multiple servers need to provide services accessible from the Internet, create multiple DNAT rules.

Prerequisites

A NAT gateway has been created.

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner and select the desired region and project.
  3. Under Network, choose NAT Gateway.
  4. On the displayed page, click the name of the NAT gateway for which you want to add the DNAT rule.
  5. On the NAT gateway details page, click the DNAT Rules tab.
  6. Click Add DNAT Rule.
    Figure 1 Add DNAT Rule

  7. Configure the parameters as prompted. For details, see Table 1.
    Table 1 Parameter descriptions

    Parameter

    Description

    Scenario

    Select VPC if your servers in a VPC will use the DNAT rule to provide services accessible from the Internet.

    Different servers in a VPC can share the same EIP to provide services accessible from the Internet.

    Port Type

    The port type. You can select All ports or Specific port.

    • All ports: This is equivalent to assigning an EIP to a server. Any requests on the EIP will be forwarded by the NAT gateway to your server based on IP address mapping.
    • Specific port: The NAT gateway only forwards requests with a specific protocol and port on the EIP to the corresponding port of the target server.

    Protocol

    The protocol can be TCP or UDP. This parameter is available if you select Specific port for Port Type. If you select All ports, the value of this parameter will be All by default.

    EIP

    The EIP that will be used by the server to provide services accessible from 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.

    Outside Port

    The port of the EIP. This parameter is available if you select Specific port for Port Type. The value ranges from 1 to 65535.

    You can enter a single port number, for example, 80.

    Private IP Address

    The private IP address of the server that provides services accessible from the Internet through the DNAT rule.

    Inside Port

    The port of the server that provides services accessible from the Internet through the DNAT rule. This parameter is available if you select Specific port for Port Type. The value ranges from 1 to 65535.

    You can enter a single port number, for example, 80.
  8. Click OK.
Parent topic: Using DNAT to Provide Services Accessible from the Internet