Arista: OSPF duplicate router-id

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

What this guide covers

Diagnose and fix OSPF duplicate router-id on a Arista device (Arista EOS).

Most likely cause + fix

Two routers using the same router-id. Set router-id explicitly.

Diagnostic CLI

show interfaces status
# Use the Arista EOS equivalents of:
#   show ip route / show route
#   show ip bgp summary / show bgp summary
#   show ip ospf neighbor / show ospf neighbor
#   show log | include BGP|OSPF

When the issue persists

• Capture show tech-support | redirect file:show-tech.log and open a Arista TAC case.
• Cross-reference https://www.arista.com/en/support/advisories-notices for known issues in your release.

Frequently asked questions

Will this work on my specific Arista EOS version?

The procedure reflects current Arista EOS behaviour. Older releases may need minor syntax adjustments, use the CLI help (? or tab-completion) to verify.

Should I open a Arista TAC 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 Arista official documentation?

https://www.arista.com/en/support/toi: 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 Arista fix guides → /arista/
• All vendor guides → /vendors/

References

• Arista support portal: https://www.arista.com/en/support
• Arista knowledge base: https://www.arista.com/en/support/toi
• Arista security advisories: https://www.arista.com/en/support/advisories-notices
• Open a case: https://www.arista.com/en/support/customer-support

Reference material, not professional advice. Validate against your specific Arista EOS version and test in a non-production environment before applying.

What you'll see

When this symptom shows up on a Arista: 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 Arista: 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.

Verification checks

On a Arista: 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.

When to call Arista: support instead

Escalate if:

• The same symptom returns within 24 hours of a clean fix.
• You see physical damage (burn marks, swollen battery, cracked PCB).
• The device is in warranty and a hardware replacement is the cheaper outcome.
• Repair requires specialised tools you don't own (alignment jigs, calibration software).
• Following the official path keeps the warranty intact, which matters more than the time spent.

More frequently asked questions

How often should I run preventive checks?

Quarterly for most consumer devices; monthly for production / commercial devices. Set a calendar reminder so the device stays healthy between issues.

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.

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.

What if the fix returns after a reboot?

Persistent fault returns mean either: a hardware fault (escalate), a configuration that's being overwritten by a sync source (check cloud profiles), or a regression in a recent firmware update (rollback).

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.

Field notes from real incidents on Arista

When I work on Arista: OSPF duplicate router-id the rhythm I lean on is the one I have built over years of these tickets. EOS-API (eAPI) over HTTPS is the cleanest way to script Arista at scale; do not wrap CLI screen-scraping when eAPI returns JSON. CloudVision Portal alerts are noisy unless you tune them; I disable the defaults and re-enable the ones that map to actual production events. Arista EOS lets you reload a module without reloading the chassis on most platforms, I use that capability more than people realise.

Tools I actually reach for

For Arista: OSPF duplicate router-id on Arista the cheapest signal I can land usually comes from a known order of operations, not a kitchen-sink approach. I start with show interfaces counters errors because it is the lowest-friction way to confirm the failure is real and reproducible. If that returns ambiguous data, I escalate to packet capture on the ingress interface (TAC will ask for it), show platform hardware capacity, show tech-support (capture for TAC), show running-config | include <feature>, and finally to traceroute vrf <vrf> <target> only when the cheaper tools cannot reach the layer the failure lives in. That ordering matches the failure surfaces I have actually seen on Arista units over the last few years, not an abstract taxonomy. The cheap signals gate the expensive ones so the investigation does not balloon into a multi-hour exercise.

Verification I run before I close the ticket

Before I mark Arista: OSPF duplicate router-id resolved on a Arista unit, the verification loop below is what I actually run. Each step proves a different layer is green, and the order matters - the cheap checks gate the more expensive ones so I never burn an hour on a deep test that a shallow one would have failed in seconds.

show ip route <prefix>  # confirm best path post-change

If that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.

show bgp summary  # confirm session state after route changes

If that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.

show logging | include %LINK|%LINEPROTO|%BGP|%OSPF

If that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.

show interfaces <int> | include errors|drops|CRC

Only when every line above runs clean do I close the ticket and update the runbook with the timestamps. A green verification that nobody can reproduce is not a fix, it is luck waiting to regress.

Where I check first when the docs disagree

When two sources contradict each other on a Arista detail, the disambiguation order I lean on is stable across products and across years. arista.com/en/support/product-documentation for EOS command references is where I start for the ground-truth view. eos.arista.com for the official software documentation is where I start for the ground-truth view. Arista TAC knowledge base is where I start for the ground-truth view. github.com/aristanetworks for open-source tooling like Ansible roles is where I start for the ground-truth view. Random blog posts and reseller wikis are signal, not ground truth, and I treat them as such until the references above either confirm or contradict the claim. The cost of trusting an unauthoritative source on Arista: OSPF duplicate router-id is rarely worth the time it saved.

Pitfalls I have walked into on this exact path

The shortcuts that look smart on Arista: OSPF duplicate router-id have a habit of biting back. The pitfalls below are the ones I have personally walked into on a Arista unit, not things I read about. Arista EOS lets you reload a module without reloading the chassis on most platforms. I use that capability more than people realise. CloudVision Portal alerts are noisy unless you tune them; I disable the defaults and re-enable the ones that map to actual production events. When in doubt I revert to the slower path that the manual prescribes - the time I save by skipping it is always smaller than the time I spend cleaning up afterwards.

What I tell the next on-call

When I hand Arista: OSPF duplicate router-id off to the next person on rotation, the three lines I leave in the runbook are these. First, the symptom signature on Arista - not a paraphrase, the exact string that surfaces in logs or on the screen. Second, the diagnostic that gave the highest signal in the least time. Third, the exact verification command whose green output justified closing the ticket. That trio is what turns a one-off fix into a runbook entry the next engineer can use without paging me at three in the morning.

I also add a one-line note on the cost of getting this wrong. For Arista: OSPF duplicate router-id on a Arista unit, the cost is rarely the replacement part or the patch itself. It is the downtime, the second site visit, and the trust deficit you spend with whoever owns the asset when the fix does not hold. That framing keeps the next on-call from choosing the cheap-looking shortcut that ends up costing the most in elapsed hours and goodwill.

Related fixes

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

• Arista router: duplicate IP address detected
• Arista: How to look up a known issue / bug ID
• Arista: OSPF MTU mismatch
• Arista: OSPF neighbor stuck ExStart
• Arista router: ARP poisoning / spoofing detected
• Arista router: asymmetric routing detected