# Size RAS gateway standby pools as an explicit availability decision

> How should active and standby gateway membership be reviewed in an SDN RAS pool?

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260908-008-size-ras-gateway-standby-pools-as-an-explicit-availability-decision/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-08T18:17:03+00:00
- Modified: 2026-09-08T18:17:13+00:00
- Last reviewed by DSE: 2026-09-08
- Resource type: Guide
- DSE priority: Information
- Topics: IT, Networks & Infrastructure
- Reading time: 1 minutes

## What you need to know

How should active and standby gateway membership be reviewed in an SDN RAS pool?

## Potentially affected

Use this review for an SDN multitenant gateway design.

## DSE recommendation

Document which active gateway failures the proposed standby allocation must cover.

## Article

## Source facts

Microsoft describes multitenant RAS Gateway as routing traffic between virtual and physical networks for enterprises or service providers. Gateway pools use M active virtual gateways with N standby gateways; N cannot exceed M. In the documented deployment, pools sit behind a software load balancer, and a tenant can have connections ending on different pools or gateways. [Microsoft documentation](https://learn.microsoft.com/en-us/windows-server/networking/sdn/technologies/network-function-virtualization/RAS-Gateway-High-Availability).

## Applicability

Use this review for an SDN multitenant gateway design. Identify the intended gateway function, pool membership, and tenant connection paths. Confirm the current supported deployment requirements before applying the architectural example.

## DSE recommendation

Document which active gateway failures the proposed standby allocation must cover. Name the tenant connections that would be included in a controlled failover exercise and the acceptable interruption for each. Ask the network owner to review placement and available capacity alongside the gateway count. Preserve the original pool design and assign responsibility for restoring standby capacity after an incident.

## Verification

During an approved exercise, record active and standby membership before and after the selected failure. Test representative tenant connections and compare the interruption with the approved objective. Check the restored steady state separately from initial recovery. Retain unsuccessful connections and capacity concerns as findings requiring follow-up.

## Official references

[Microsoft Learn: RAS Gateway High Availability](https://learn.microsoft.com/en-us/windows-server/networking/sdn/technologies/network-function-virtualization/RAS-Gateway-High-Availability). Source reviewed September 8, 2026.

## Primary reference

- Name: RAS Gateway High Availability
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/windows-server/networking/sdn/technologies/network-function-virtualization/RAS-Gateway-High-Availability
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Size RAS gateway standby pools as an explicit availability decision,” DSE Security, https://update.dsesecurity.com/updates/dse-20260908-008-size-ras-gateway-standby-pools-as-an-explicit-availability-decision/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
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