Nvidia (Mellanox) Switch Port stuck disabled by link-flap: How to Fix
By Sai Kiran Pandrala · reviewed by Sai Kiran Pandrala, Editor Last verified: 2026-05-30
| Vendor | Nvidia (Mellanox) |
|---|---|
| Operating system | Cumulus Linux / NVOS / SONiC |
| Category | Port Recovery |
| Skill level | Intermediate to advanced |
| DIY-able? | Yes with CLI access; some scenarios need Nvidia Enterprise Support + RMA. |
What this guide covers
Resolve a Nvidia (Mellanox) switch port link-flap.
Cause + fix
Port flapped past the threshold. Fix the cable / SFP first, then raise the flap threshold.
CLI / commands
nv show interface
nv show interface swp1
# Apply the fix above, then bounce the port:
nv config (NVUE)
# (interface shutdown / no shutdown, vendor-specific)
nv config save
Avoid recurrence
- Identify and remove the source of the violation (BPDU, MAC, storm).
- Tune the protection threshold if it's too aggressive for normal traffic.
- Add monitoring for repeat events.
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
Related fixes
Related guides worth a look while you sort this one out:
- Nvidia (Mellanox) Switch Port stuck disabled by BPDU guard: How to Fix
- Nvidia (Mellanox) Switch Port stuck disabled by loop detection: How to Fix
- Nvidia (Mellanox) Switch Port stuck disabled by PoE budget exceeded: How to Fix
- Nvidia (Mellanox) Switch Port stuck disabled by port security violation: How to Fix
- Nvidia (Mellanox) Switch Port stuck disabled by storm-control: How to Fix
- Nvidia (Mellanox) Switch Port stuck disabled by UDLD: How to Fix
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.
What changed recently?
Fault diagnosis on a Nvidia device goes faster when you map the symptom to a recent change:
- Did firmware update in the last 7 days?
- Did the network (router, ISP, VPN) change?
- Was the device moved physically?
- Did paired devices (phone, hub, app) update?
- Were any accessories swapped in or out?
The answer narrows the root cause to a manageable subset.
Before you start
A few things to confirm so the Nvidia device fix goes cleanly:
- Latest firmware downloaded if you're going to update.
- Warranty + support contract status checked: opening sealed parts may void it.
- Backup of current configuration (where applicable) taken.
- Spare parts on hand if you anticipate replacement.
- Adequate workspace, lighting, and time, rushing causes regressions.
Verification checklist
After applying the fix on your Nvidia device, confirm:
- The original symptom is no longer reproducible.
- Related features (status LEDs, app sync, paired accessories) still work.
- The device responds to a soft reboot without the fault returning.
- Any error codes that were on display have cleared.
- Documentation (your service log, the brand companion app) reflects the change.
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.
Does this affect other devices on my network?
Generally no. The procedure is local to this device. Network-side changes (firmware updates that affect TLS, SMB, or routing) are flagged explicitly in the steps.
Is it safe to apply during business hours?
If the device is in production use, apply during a scheduled maintenance window. Most procedures need 2-15 minutes of downtime. Capture pre-change state so you can roll back if needed.
How long does this fix usually take?
Most users complete the steps in 20-45 minutes the first time, and 5-10 minutes on subsequent runs once the menu paths are familiar.
Will this void my warranty?
Applying official firmware updates and following the user manual will not affect warranty. Opening sealed components, jumping safety circuits, or using third-party parts can void warranty in most jurisdictions.