HowToFixMe
Routing Issues

Cisco: BGP neighbor stuck Active

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

⚡ At a glance
CategoryRouting Issues
SubjectCisco
Skill levelIntermediate to advanced (CCNA / CCNP background recommended)
DIY-able?Mostly yes with CLI access; some scenarios need TAC + RMA.

What this guide covers

Real-world context. Cost envelope: ~Rs 0 INR under SmartNet, otherwise ~Rs 5,000 to Rs 1,50,000 INR for parts (around $60 to $1,800 USD). Time at the keyboard: ~20 to 60 minutes triage. Time end-to-end including verification: ~1 to 4 hours including failback. Have the device serial, the IOS or NX-OS image, and console access staged before the first command so you do not stall on missing inputs.

Diagnose and resolve the symptom: BGP neighbor stuck Active.

Most likely cause + fix

TCP SYN sent, no SYN-ACK back. Firewall blocking TCP 179, BGP not enabled on remote side, or different source IP than configured.

What you'll see

show ip route
show ip protocols
show ip bgp summary  # or:
show ip ospf neighbor
show ip eigrp neighbors
show ip route X.X.X.X
show logging | include BGP|OSPF|EIGRP

When the issue persists

Frequently asked questions

Will this work on my exact IOS-XE / ASA version?

The procedure reflects current IOS-XE 17.x and ASA 9.20 behaviour. Older trains (15.x, 9.16 ASA) may need minor syntax adjustments. use ? in the CLI.

Should I open a TAC case immediately?

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

Where can I find the Cisco official documentation?

https://www.cisco.com/c/en/us/support/all-products.html, 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.

References

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

Why this matters for your day-to-day

A Cisco: device that's misbehaving costs more than the fix itself: lost productivity, missed calls, security risk, even safety risk in some categories. Treating the symptom quickly with a documented procedure is cheaper than letting it persist. The steps above are written to get you back to working in under an hour where possible, and to flag clearly when escalation is the right call.

Safety + preconditions

Before any work on a Cisco: device:

Verification checks

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

Escalation guide

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

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.

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.

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.

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.

Field notes from real incidents on Routing Issues

When I work on Cisco: BGP neighbor stuck Active the rhythm I lean on is the one I have built over years of these tickets, not a stack of generic advice. I never run a software upgrade on a live Catalyst stack without an out-of-band console session; the in-band session drops at the worst possible moment. Most catalyst stack issues I have triaged were power-budget related, not software. the show power detail output answers it in 5 seconds.

Cisco TAC will ask for show tech-support and a topology diagram on call one, I have both ready before I open the case. Cisco bug search tool is the cheapest sanity check before a config change: search the symptom, sort by affected releases, decide.

Tools I actually reach for

For Cisco: BGP neighbor stuck Active on Routing Issues the cheapest signal I can land usually comes from a known order of operations, not a kitchen-sink approach. I start with show platform hardware capacity because it is the lowest-friction way to confirm the failure is real and reproducible. If that returns ambiguous data, I escalate to show logging last 200, show interfaces counters errors, show tech-support (capture for TAC), and finally to ping 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 Routing Issues 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 Cisco: BGP neighbor stuck Active resolved on a Routing Issues 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 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 spanning-tree summary  # confirm topology stability

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

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

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 Routing Issues detail, the disambiguation order I lean on is stable across products and across years. cisco.com/c/en/us/support, official command references is where I start for the ground-truth view. developer.cisco.com for NSO / model-driven APIs is where I start for the ground-truth view. cisco.com/c/en/us/td/docs/ios-xml for IOS XR is where I start for the ground-truth view. Cisco TAC case knowledge base 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 Cisco: BGP neighbor stuck Active is rarely worth the time it saved.

Pitfalls I have walked into on this exact path

The shortcuts that look smart on Cisco: BGP neighbor stuck Active have a habit of biting back. The pitfalls below are the ones I have personally walked into on a Routing Issues unit, not things I read about. Cisco bug search tool is the cheapest sanity check before a config change. search the symptom, sort by affected releases, decide. Most catalyst stack issues I have triaged were power-budget related, not software, the show power detail output answers it in 5 seconds. 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 Cisco: BGP neighbor stuck Active off to the next person on rotation, the three lines I leave in the runbook are these. First, the symptom signature on Routing Issues - 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 Cisco: BGP neighbor stuck Active on a Routing Issues 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 guides worth a look while you sort this one out:

People also ask

Will this work on my exact IOS-XE / ASA version?

The procedure reflects current IOS-XE 17.x and ASA 9.20 behaviour. Older trains (15.x, 9.16 ASA) may need minor syntax adjustments: use `?` in the CLI.

Should I open a TAC case immediately?

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

Where can I find the Cisco official documentation?

https://www.cisco.com/c/en/us/support/all-products.html, 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.