What Is Azure NAT Gateway

URL: https://learn.microsoft.com/en-us/azure/nat-gateway/nat-overview
Author: asudbring

Summary

Overview of Azure NAT Gateway features, resources, architecture, and implementation. Learn how Azure NAT Gateway works and how to use NAT gateway resources in Azure.

Highlights Added July 17, 2024 at 11:02 AM

Azure NAT Gateway is a fully managed and highly resilient Network Address Translation (NAT) service. You can use Azure NAT Gateway to let all instances in a private subnet connect outbound to the internet while remaining fully private. Unsolicited inbound connections from the internet aren't permitted through a NAT gateway. Only packets arriving as response packets to an outbound connection can pass through a NAT gateway.
NAT Gateway provides dynamic SNAT port functionality to automatically scale outbound connectivity and reduce the risk of SNAT port exhaustion. ([View Highlight] (https://read.readwise.io/read/01h9fwryafshg9wsnnjh9c6tj0))

NAT gateway replaces a subnet’s default route to the internet when configured. All traffic within the 0.0.0.0/0 prefix has a next hop type to NAT gateway before connecting outbound to the internet. ([View Highlight] (https://read.readwise.io/read/01h9fwsyvq7f9sdztywz09ma08))

You can override NAT gateway as a subnet’s next hop to the internet with the creation of a custom user-defined route (UDR). ([View Highlight] (https://read.readwise.io/read/01h9fwvvkk7krjsk2ssbfq7j41))

Presence of custom UDRs for virtual appliances and ExpressRoute override NAT gateway for directing internet bound traffic (route to the 0.0.0.0/0 address prefix). ([View Highlight] (https://read.readwise.io/read/01h9fwvqdw1mthvntsfw1x1gap))