Help Center/ NAT Gateway/ User Guide (Kuala Lumpur Region)/ Overview/ NAT Gateway Types
Updated on 2022-08-16 GMT+08:00
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NAT Gateway Types

A NAT gateway type specifies the maximum number of SNAT connections supported by a NAT gateway.

An SNAT connection consists of the source IP address, source port, destination IP address, destination port, and transmission-layer protocol. The source IP address refers to the EIP, and the source port refers to the EIP port. They will be used to access the destination IP address and port of the Internet. These five elements identify a connection as a unique session.

The data throughput of a NAT gateway is determined by the sum of the EIP bandwidths used by its DNAT rules. For example, if a NAT gateway has two DNAT rules, and their EIP bandwidths are 10 Mbit/s and 5 Mbit/s, respectively, the throughput of the NAT gateway is 15 Mbit/s.

Each NAT gateway supports up to 20 Gbit/s of bandwidth.

The timeout period of an SNAT connection using TCP is 600 seconds.

The timeout period of an SNAT connection using UDP is 300 seconds.

When creating a NAT gateway, select the type based on your service requirements. Table 1 lists the NAT gateway types.
Table 1 NAT gateway types

Type

Maximum Number of SNAT Connections

Small

10,000

Medium

50,000

Large

200,000

Extra-large

1,000,000
  • If the requests exceed the maximum connections allowed by your NAT gateway, your services will be adversely affected. To avoid this situation, create alarm rules for the SNAT connection in Cloud Eye.
  • The DNAT rules of a NAT gateway are irrelevant to the NAT gateway type. A maximum of 200 DNAT rules can be added to a NAT gateway.
Parent topic: Overview