# Keep Linux guest adapter identity stable during cluster failover

> What network-adapter settings should be reviewed before failing over a Linux VM?

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260908-124-keep-linux-guest-adapter-identity-stable-during-cluster-failover/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-08T18:15:07+00:00
- Modified: 2026-09-08T18:23:27+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

What network-adapter settings should be reviewed before failing over a Linux VM?

## Potentially affected

Administrators operating Linux VMs on Hyper-V failover clusters.

## DSE recommendation

Record the expected guest interface names and addresses alongside the configured virtual adapters.

## Article

## Source facts

Microsoft recommends a static MAC address for every virtual adapter of a clustered Linux VM. Some Linux versions can lose network configuration after failover if a different MAC address is assigned. Its Linux guidance also recommends the Hyper-V-specific virtual Ethernet adapter. Mixing legacy and Hyper-V-specific adapters can produce unexpected interface names, so Microsoft advises removing legacy adapters when using the Hyper-V-specific adapter. [Microsoft documentation](https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/Best-Practices-for-running-Linux-on-Hyper-V).

## Applicability

Identify the Linux distribution and release, guest integration components, adapter types, MAC assignments, and network configuration files. Check the distribution-specific support guidance before changing guest networking.

## DSE recommendation

Record the expected guest interface names and addresses alongside the configured virtual adapters. Have the Linux and virtualization owners review the mapping and approve any removal of an unused legacy adapter. Define a recovery route that does not depend solely on the interface being changed.

## Verification

Test a controlled cluster move and compare the guest’s adapter identities and connectivity before and afterward. Include a guest restart and an application transaction using the intended interface. Record an unexpected rename or missing network configuration as a failure to resolve before scheduling routine failover operations.

## Official references

[Microsoft Learn: Best Practices for running Linux on Hyper-V](https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/Best-Practices-for-running-Linux-on-Hyper-V). Source reviewed September 8, 2026.

## Primary reference

- Name: Best Practices for running Linux on Hyper-V
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/Best-Practices-for-running-Linux-on-Hyper-V
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Keep Linux guest adapter identity stable during cluster failover,” DSE Security, https://update.dsesecurity.com/updates/dse-20260908-124-keep-linux-guest-adapter-identity-stable-during-cluster-failover/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
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