NAT Gateway:Functions and features

Feature Category

Feature Set

Description

Reference

Manage instances

Enhanced features

Internet NAT gateways provide enhanced features such as EIP affinity and throttling of source IP addresses to help you adjust the forwarding behavior in special network scenarios.

Manage NAT Entries

Manage SNAT entries

Configure SNAT entries for cloud resources such as ECS instances that require outbound internet access. You can configure SNAT at the VPC, vSwitch, ECS instance, elastic network interface, or custom CIDR level, bind multiple NAT IPs or EIPs, and enable IP affinity.

Manage DNAT entries

Use DNAT entries to forward inbound internet traffic to backend servers. DNAT supports IP mapping, port mapping, and port range mapping, and can share the same NAT IP or EIP with SNAT.

Manage EIPs

Manage lifecycle

Bind or unbind elastic IP addresses (EIPs) to or from a public NAT gateway to manage the public IP addresses required for outbound internet access.

EIP binding mode

Two EIP binding modes are supported: standard EIP mode and multi-EIP connection mode, addressing different requirements for how outbound public IP addresses are presented.

Manage NAT IP

Manage lifecycle

Bind or unbind NAT IPs to or from a VPC NAT gateway to manage the address resources used for private network traffic forwarding.

NAT IP Allocation Mode

NAT IP addresses can be randomly assigned or manually assigned to NAT CIDs to flexibly control how private forwarding addresses are assigned.

NAT IP Type

Allocate NAT IPs from a NAT IP range either randomly or by manual specification, providing flexible control over how private network traffic forwarding addresses are assigned.

NAT IP Attributes

NAT IP ranges support prefix lengths from /16 to /32, with a default range provided for quick address planning.

Feature Category

Feature Set

Description

Reference

Billing method

Pay-as-you-go

Public NAT gateways support pay-as-you-go billing, allowing you to pay only for actual usage.

CU Package

CU Package

Purchase NAT gateway resource packs (CU packs) to offset usage, with self-service cancellation supported to help reduce costs.

Billable Item

Billable items

NAT gateway charges consist of instance fees and capacity unit (CU) fees. See the billing documentation for pricing details and how each fee is calculated.

Feature Category

Feature Set

Description

Reference Documentation

Basic product monitoring

Metrics

Monitor metrics such as bandwidth (bps/pps), concurrent connections, new connection rate, dropped packets due to concurrent connection limit exceeded, and dropped packets due to new connection rate limit exceeded to track the health and performance of your NAT gateway in real time.

Events

Configure threshold alert rules for bandwidth limits, concurrent session limits, SNAT port allocation failures, and other events to detect and resolve issues in a timely manner.

Intelligent O&M

Self-service diagnosis

Built-in diagnostics and path analysis tools help you quickly identify network connectivity issues.

Feature Category

Feature Set

Description

Reference

Manage elastic quota

Elastic quota

Internet NAT gateways support elastic scaling, with performance scaling up to 20 Gbps bandwidth, 2 million concurrent connections, and 100,000 CPS.

Manage elastic SLA

Scaling efficiency

Auto-scaling is supported, allowing bandwidth to increase by 50% within 5 minutes when scaling from 5 Gbps to 20 Gbps on a single instance, enabling rapid response to traffic surges.

Manage elastic capacity

Basic Capacity

An Internet NAT gateway provides a base capacity of 5 Gbps bandwidth, 500,000 concurrent connections, and 20,000 CPS, sufficient for typical internet traffic forwarding requirements.

Feature Category

Feature Set

Description

Reference

Manage SLA

Single-zone

Internet NAT gateways deployed in a single zone provide a 99.95% service availability.

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Multi-zone

Internet NAT gateways deployed across multiple availability zones provide a 99.995% availability SLA for higher reliability.

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Feature Category

Feature Set

Description

Reference

Manage quota

Number of NAT gateways that can be configured for a VPC

The default quota for NAT gateways per VPC is 5, and you can request quota increases as needed.

Number of EIPs that can be associated with a single Internet NAT gateway (in passthrough mode)

By default, the number of EIPs that can be associated with a single Internet NAT gateway is 15, and the maximum number can be increased to 50.

Number of EIPs that can be associated with a single Internet NAT gateway (passthrough mode)

By default, 15 EIPs can be associated with a single Internet NAT gateway in passthrough mode. You can increase the maximum number of EIPs to 512.

Number of NAT IP addresses that can be associated with a VPC NAT gateway

A single VPC NAT gateway supports up to 15 NAT IPs by default, with a maximum of 50 available upon request.

Number of DNAT entries that can be created in each NAT gateway

A NAT gateway supports up to 40 DNAT entries by default, with a maximum of 3,000 available upon request.

Number of SNAT entries that can be created in each NAT gateway

A NAT gateway supports up to 40 SNAT entries by default, with a maximum of 2,500 available upon request.

Feature Category

Feature Set

Description

Reference

Route

Custom Route Tables

Configure NAT gateways as the next hop in custom route tables to direct specific traffic through the NAT gateway.

O&M

Flow logs

Internet NAT gateways support session logging (flow logs) that record session information traversing the gateway, useful for traffic tracing and troubleshooting.