What Is NAT Gateway?

The NAT Gateway service provides the network address translation (NAT) function with 10 Gbit/s bandwidth for servers, such as Elastic Cloud Servers (ECSs), Bare Metal Servers (BMSs), and Workspace desktops, in a Virtual Private Cloud (VPC), or servers that connect to a VPC through Direct Connect or Virtual Private Network (VPN) in local data centers, allowing these servers to share elastic IP addresses (EIPs) to access the Internet or to provide services accessible from the Internet.

NAT Gateway supports source NAT (SNAT) and destination NAT (DNAT) functions.

• The SNAT function translates private IP addresses into EIPs, allowing servers in a VPC to share an EIP to access the Internet in a secure and efficient way.
  Figure 1 shows the SNAT architecture.

  Figure 1 SNAT architecture
  

• The DNAT function enables servers in a VPC to share an EIP to provide services accessible from the Internet through IP address mapping or port mapping.

  Figure 2 shows the DNAT architecture.

  Figure 2 DNAT architecture