Nvidia (Mellanox) switch: MAC table full

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

What this guide covers

Fix MAC table full on a Nvidia (Mellanox) switch.

Step-by-step

1. Check current MAC table utilisation.
2. Identify the offending VLAN or port.
3. Enable storm-control on access ports.
4. Enable port-security with a hard MAC limit.
5. Long-term, refresh to a switch with a larger MAC table.

CLI / commands

nv show interface
nv show interface swp1
nv show platform inventory

When the issue persists

• Open a Nvidia Enterprise Support case with the tech-support bundle.
• Provide the timeline + recent changes.

Frequently asked questions

Will this work on my specific Cumulus Linux / NVOS / SONiC version?

The procedure reflects current Cumulus Linux / NVOS / SONiC behaviour. Older releases may need minor syntax adjustments. use the CLI help (? or tab-completion) to verify.

Should I open a Nvidia Enterprise Support 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 Nvidia (Mellanox) official documentation?

https://docs.nvidia.com/networking/, 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.

Related guides

• All Nvidia (Mellanox) fix guides → /nvidia/
• All vendor guides → /vendors/

Related fixes

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

• Nvidia (Mellanox) switch: MAC address flapping between ports
• Best Nvidia (Mellanox) switch for branch office
• Best Nvidia (Mellanox) switch for enterprise data centre
• Best Nvidia (Mellanox) switch for retail store
• Best Nvidia (Mellanox) switch for SD-WAN deployment
• Best Nvidia (Mellanox) switch for small office

References

• Nvidia (Mellanox) support portal: https://enterprise-support.nvidia.com/
• Nvidia (Mellanox) knowledge base: https://docs.nvidia.com/networking/
• Nvidia (Mellanox) security advisories: https://www.nvidia.com/en-us/security/
• Open a case: https://enterprise-support.nvidia.com/s/createcase

Reference material, not professional advice. Validate against your specific Cumulus Linux / NVOS / SONiC version and test in a non-production environment before applying.

Common patterns we see

When this symptom shows up on a Nvidia 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 Nvidia 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.

How to confirm it's actually fixed

On a Nvidia 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 Nvidia device, the right escalation depends on impact:

• Cosmetic / minor: log a ticket via the Nvidia 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.

More frequently asked questions

Are there safer alternatives for non-technical users?

Yes: the manufacturer's self-service troubleshooter (HP Smart, LG ThinQ, Samsung Members, similar) usually walks through the same steps in a guided UI. Use that first if you're not comfortable with menu paths.

What if my model isn't exactly the same revision?

Cross-check the model code on the rating plate against the manufacturer support page. Major firmware generations sometimes shift the menu path; the option is usually under a similarly-named section.

Will the procedure work on the international variant?

Some features and firmware paths are region-locked. Check the model spec sheet to confirm your variant supports the menu option referenced. If you're outside the US/EU, look for the regional support portal.

Can I roll this back if something breaks?

Yes for software-level changes (firmware rollback, config rollback). Hardware changes are usually one-way. Always back up settings before starting.

Why is this happening on a brand-new unit?

Out-of-box defects do occur. If you've owned the device under 30 days and the symptom persists after a factory reset, escalate to the seller for replacement under DOA terms before opening a manufacturer support case.