Help Center/ NAT Gateway/ Service Overview/ Functions
Updated on 2026-04-16 GMT+08:00
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Functions

Public NAT Gateway

Public NAT gateways provide network address translation (NAT) with 20 Gbit/s of bandwidth for servers in a VPC or for servers in on-premises data centers that connect to a VPC through Direct Connect or VPN.

Public NAT gateways provide source NAT (SNAT) and destination NAT (DNAT).
  • SNAT translates private IP addresses into EIPs, allowing servers within an AZ or across AZs in a VPC to share an EIP to access the Internet.
  • DNAT enables servers within an AZ or across AZs in a VPC to share an EIP to provide services accessible from the Internet. With an EIP, a public NAT gateway forwards the Internet requests from only a specific port over a specific protocol to the specified port of a server, or it can forward all requests to the private IP address of a server regardless of which port they originated on.

Private NAT Gateway

Private NAT gateways provide private address translation (NAT) for cloud servers (ECSs and BMSs) in a VPC. You can configure SNAT and DNAT rules to translate the source and destination IP addresses into transit IP addresses, so that servers in a VPC can communicate with other VPCs or on-premises data centers.

Private NAT gateways provide source NAT (SNAT) and destination NAT (DNAT).
  • SNAT enables servers within an AZ or across AZs in a VPC to share a transit IP address to access servers in remote private networks, like servers in an on-premises data center or a different VPC.
  • DNAT enables servers within an AZ or across AZs in a VPC to share a transit IP address to provide services accessible from servers in remote private networks, like servers in an on-premises data center or a different VPC.