IP / Network Issue

Dell switch: MAC address flapping between ports

Q: Where can I find the Dell official documentation?

https://www.dell.com/support/kbdoc — search the product family + feature name.

By Sai Kiran Pandrala · reviewed by Sai Kiran Pandrala, Editor Last verified: 2026-05-30

⚡ At a glance

Vendor	Dell
Operating system	Dell OS10 / SmartFabric OS
Category	IP / Network Issue
Skill level	Intermediate to advanced
DIY-able?	Yes with CLI access; some scenarios need Dell ProSupport + RMA.

What this guide covers

Real-world context. Cost envelope: ~Rs 0 INR under ProSupport, otherwise ~Rs 3,000 to Rs 40,000 INR for parts (around $36 to $480 USD). Time at the keyboard: ~20 to 60 minutes hands-on. Time end-to-end including verification: ~1 to 4 hours including SupportAssist scan. Have the service tag, the SupportAssist export, and a USB recovery stick staged before the first command so you do not stall on missing inputs.

Fix MAC address flapping between ports on a Dell switch.

Full fix path

Identify which ports the MAC is bouncing between.
If both ports go to access devices. someone hooked the same device to both, disconnect one.
If one is an uplink: STP loop, bring BPDU guard / loop-guard / UDLD online.
Rate-limit MAC moves to suppress event spam.

CLI / commands

show interface status
show interface ethernet 1/1/1
show inventory

When the issue persists

Open a Dell ProSupport case with the tech-support bundle.
Provide the timeline + recent changes.

Frequently asked questions

Will this work on my specific Dell OS10 / SmartFabric OS version?

The procedure reflects current Dell OS10 / SmartFabric OS behaviour. Older releases may need minor syntax adjustments. use the CLI help (? or tab-completion) to verify.

Should I open a Dell ProSupport case immediately?

Open one if you suspect hardware failure or the symptom persists after a maintenance-window reload. Make sure your support entitlement is active first.

Where can I find the Dell official documentation?

https://www.dell.com/support/kbdoc, search the product family + feature name.

Is this procedure safe in production?

Test in a lab or maintenance window first. Capture pre-change state so you can roll back.

All Dell fix guides → /dell/
All vendor guides → /vendors/

Related guides worth a look while you sort this one out:

References

Dell support portal: https://www.dell.com/support
Dell knowledge base: https://www.dell.com/support/kbdoc
Dell security advisories: https://www.dell.com/support/security
Open a case: https://www.dell.com/support/incidents-online

Reference material, not professional advice. Validate against your specific Dell OS10 / SmartFabric OS version and test in a non-production environment before applying.

Spot the symptom

When this symptom shows up on a Dell device, three patterns repeat:

1. Recent firmware update changed behavior: the symptom started within a week of an OTA push. Rollback or wait for the hotfix. 2. Environmental trigger, temperature, humidity, line voltage, network changes. Look at what changed in the environment. 3. Cumulative wear. components like batteries, gaskets, fans degrade over time. Replace the consumable rather than chasing a software fix.

Knowing which pattern applies saves time on the wrong fix.

Safety + preconditions

Before any work on a Dell device:

Unplug from mains for any internal-access procedure.
Discharge stored energy (capacitors in PSUs, residual battery charge) per manufacturer guidance.
Use ESD-safe handling for boards and modules, no carpet, no wool sleeves.
Avoid moisture; never apply liquids near vents or connectors.
If you smell smoke, see scorch marks, or feel uneven heat, stop and escalate.

Confirm it stuck

On a Dell device, the test is rarely "reboot and see". Use this list:

Active reproduction: trigger the original failure path on purpose.
Indirect reproduction: do an activity that would expose the same subsystem.
Status indicator review: every LED / display / app status should be green.
24-hour soak: leave the device under normal load overnight; check the next morning.
Telemetry check: review the device or app's diagnostic log for new error entries.

Escalation guide

For a Dell device, the right escalation depends on impact:

Cosmetic / minor: log a ticket via the Dell app or web portal. Response 1-3 business days.
Mid-impact: phone support. Have your serial number ready.
Critical (production down, safety issue): in-person dealer / TAC visit. Bring proof of purchase.
Out of warranty: third-party repair shop with manufacturer-certified technicians.