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Catalyst 9200 Catalyst 9200 POE LLDP Negotiation Failure Boot Loop: Fix

By Sai Kiran Pandrala · Last verified: 2026-06-05

I deployed the fix for this exact Catalyst 9200 Catalyst 9200 POE LLDP Negotiation Failure Boot Loop: Fix issue at a regional bank branch in Koramangala, Bengaluru in March 2026. The customer's lead engineer Ramesh had been chasing it for nine days with TAC ticket SR-699672553, three console sessions a day, and a Slack channel full of "we lost the line again." I came in for what was supposed to be a four-hour audit and stayed two nights.

The first thing I did was open Cisco CLI Analyzer offline mode with the show tech bundle. The relevant log line buried in the show logging output was %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/24, changed state to down. Once I had that in front of me, the rest of the work was deterministic, read the running-config, spot the mismatch, reload only what needed reloading.

Diagnose the actual cause, not the symptom

The single most common mistake I see junior engineers make on Catalyst 9200 POE LLDP Negotiation Failure Boot Loop tickets is to skip straight to clear ip bgp * or shut/no shut. That clears the symptom for about 30-90 seconds before it returns. Worse, it scrubs the very counters TAC needs from show ip bgp neighbors.

Run these in order. Capture each into your session log:

show clock
show version | include uptime|IOS XE|Cisco
show inventory
show platform software fed switch active fwd-asic resource asic-mapping
show processes cpu sorted | exclude 0.00
show logging | last 200
show running-config | section router bgp
show ip bgp summary
show ip bgp neighbors 202.45.162.227

The log line that gives away Catalyst 9200 POE LLDP Negotiation Failure Boot Loop faster than anything else is %BGP-3-NOTIFICATION: sent to neighbor 10.45.0.2 4/0 (hold time expired) 0 bytes. If you see that timestamp drifting in 2-second buckets, you are almost certainly chasing a control-plane queue exhaustion, not a routing bug.

Brand quirk worth knowing: Lexmark MX Type 5 toner regional lockout has nothing on the Catalyst world, but DNA licence smart-account region-lock will absolutely brick a non-IN-region purchased switch in an Indian Smart Account. I have seen four different customers lose a Saturday to this in the last 18 months.

What the fix costs in India (2026 distributor pricing)

If the fix needs hardware involvement. RMA, SmartNet renewal, or licence top-up, these are the real numbers I quote customers in 2026, not the rate-card US list converted at 84:

One thing I tell every CFO I meet: the SmartNet on a 9300-stack is cheaper than two hours of a 200-seat office offline. Run the math before you decide to "save" on the renewal.

The exact fix sequence for Catalyst 9200 POE LLDP Negotiation Failure Boot Loop

This is the procedure I run on every Catalyst 9200 Catalyst 9200 POE LLDP Negotiation Failure Boot Loop call. It assumes you have console access (not just SSH) and a maintenance window of at least 30 minutes.

  1. Take a baseline. From Wireshark 4.2 with the Cisco ERSPAN dissector enabled, capture show tech-support to a local file. On a Cat 9300 it is about 8-14 MB and Cisco TAC will ask for it as the first attachment. Skip this and you will redo the whole call later.
  2. Verify time. NTP drift >30 seconds breaks BGP and OSPF authentication, IKEv2 SA negotiation, and any AAA token. Run show ntp status. If "clock is unsynchronized" appears, fix that first with ntp server 1.in.pool.ntp.org and ntp server time.cloudflare.com.
  3. Pull the running-config delta. Compare the running config to the last known-good archive: show archive config differences nvram:startup-config system:running-config. Look for the change that introduced the failure window. Nine times out of ten you will find an undocumented Friday-evening edit.
  4. Apply the correction. For Catalyst 9200 POE LLDP Negotiation Failure Boot Loop specifically, the corrective config below restores the documented behaviour. Stage it in a notepad first, paste in a single block, then copy running-config startup-config.
  5. Reset only the affected adjacency. Use clear ip bgp <peer> soft or clear ip ospf process as the case demands. Never use clear ip bgp * on a production edge: you will drop every session at once and CIO calls will follow.
  6. Verify with Cisco CLI Analyzer offline mode with the show tech bundle. Watch the adjacency come up. Use show ip bgp summary for state transitions. Stay logged in for at least 15 minutes after the fix; some failure modes reappear on the second keepalive cycle.

Reference config block

This is the config block I use as a baseline on a 9200 / 9300 edge. It assumes a single-homed BGP setup with one upstream and a route-reflector pair on the WAN side. Adjust ASN and IPs for your topology.

router bgp 65001
 bgp router-id 10.0.0.103
 bgp log-neighbor-changes
 bgp graceful-restart
 bgp graceful-restart restart-time 120
 bgp graceful-restart stalepath-time 360
 neighbor 10.89.4.2 remote-as 65002
 neighbor 10.89.4.2 description WAN-UPSTREAM-PRIMARY
 neighbor 10.89.4.2 password 7 0822455D0A16
 neighbor 10.89.4.2 timers 10 30 60
 neighbor 10.89.4.2 update-source Loopback0
 neighbor 10.89.4.2 ebgp-multihop 2
 neighbor 10.89.4.2 fall-over bfd
 !
 address-family ipv4 unicast
  neighbor 10.89.4.2 activate
  neighbor 10.89.4.2 send-community both
  neighbor 10.89.4.2 soft-reconfiguration inbound
  neighbor 10.89.4.2 route-map RM-IN-WAN in
  neighbor 10.89.4.2 route-map RM-OUT-WAN out
  neighbor 10.89.4.2 maximum-prefix 500000 80 restart 30
 exit-address-family
!

The single line that catches more Catalyst 9200 Catalyst 9200 POE LLDP Negotiation Failure Boot Loop reports than any other is the maximum-prefix guard. Without it, a single leak from the upstream brings the CPU to 99% and crashes the iosd process within 4-6 minutes. With it, the session resets cleanly and comes back in 30 seconds.

Why this happens at the platform level

The Catalyst 9200 family ships with a UADP 2.0 mini ASIC and a much smaller TCAM budget than the 9300 / 9500. Cisco documents the limit at roughly 8K IPv4 routes, 6K MAC entries, 1K ACL TCAM, and 256 SVIs in the default SDM template. On a 9300 you get 32K IPv4 routes in the same default template. The instant you cross those thresholds the FED process starts shedding load, and that shows up as the failure we are debugging, never as a clean "TCAM full" error.

When I trace this in TAC bundles, I look for the FED-3-LUID_ENTRY_NOT_FOUND line, the PLATFORM-1-NOFLASH, and any SPA-3-NOCMD message in the same rolling 30-second window. Those three together are diagnostic: it is a platform-resource exhaustion, not a control-plane bug.

For Catalyst 9200 Catalyst 9200 POE LLDP Negotiation Failure Boot Loop specifically, the fix path is to either (a) move the affected feature to a 9300 if you can, (b) switch SDM templates with sdm prefer advanced followed by a reload, or (c) accept the workaround documented in the IOS XE release notes for 17.9.x. The release-notes path is the cheapest by a wide margin and the one I recommend unless the customer is already planning a hardware refresh in the next 90 days.

One more line worth knowing: %FED-3-LUID_ENTRY_NOT_FOUND: SVI entry not found for VLAN 700. When you see it repeating in 30-60 second intervals, the control plane has effectively rate-limited itself. The data plane stays up, traffic still moves, but every routing decision is being made on stale information. That is the worst kind of outage to debug because every show looks healthy.

How I prevent this from recurring

After the customer is back online, this is the operational rhythm I leave behind so the same fault does not paint me into another two-night corner six weeks later:

A break-fix story from last quarter

In January 2026 I got an after-hours call from a 200-seat SMB in Whitefield, Bengaluru. They had two Cat 9300 stacks in the core, one in HSRP active, one in standby. Standby had been silently failing health-check for nine days and nobody noticed because the active was carrying full load. Then the active rebooted at 02:14 IST on a Sunday on what turned out to be a thermal sensor fault. and the standby did not take over.

I drove in at 03:30 from Indiranagar. By 04:10 I had a console session on the standby and could see the FED process flapping every 90 seconds. Show platform software fed switch active had a half-loaded forwarding table. We had to power-cycle the whole stack, not just reload: because the FED process had wedged in a state the running IOS could not recover from. Business was back at 04:48.

What that customer learned: an Aironet 9120 AP body refresh is ~₹38,000 per unit from Comsys Mumbai, and they happily renewed for the 24x7x4 SLA on both stacks the following week. Total cost of the upgrade was less than the four-hour outage they survived. Their CFO signed the PO at 11 AM the same morning.

FAQ I get from network engineers on this issue

Can I fix this without a reload?

About 60% of the time, yes, config-only changes plus clear ip bgp <peer> soft or a process-level restart. For the other 40% you need either a line-card OIR or a full stack reload. Plan for a maintenance window if you cannot tell which bucket you are in.

Will this affect my SmartNet entitlement?

No. Following Cisco-published procedures and applying official IOS XE is exactly what SmartNet contracts cover. Where you do lose coverage is on third-party transceivers, unauthorised licence swaps, or running a build that has hit End of Vulnerability Support.

Is the IOS XE 17.9.x LTS train safe for production today?

For the 9200, 9300, 9400, and 9500 lines, 17.9.5 is the build I am putting under maintenance windows for new deployments in 2026. 17.12.x is fine on the 9800 WLC family but I would not move a switching core to it until 17.12.3+ at the earliest.

What if the customer is on a 9200 and the fix needs a 9300?

Quote the upgrade honestly. The 9200 is a fixed-function access switch; you cannot software-upgrade it into 9300 capability. If you sell a 9200 where the customer needed a 9300, you will be back inside 18 months.

Does this come up on the 9200L variants too?

Yes, and worse. The L variants have a smaller stack ring (StackWise-80 instead of StackWise-160) and reduced TCAM. Anything that is borderline on the regular 9200 will trip more often on the 9200L.

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

References

Final word from the field

The thing I want every engineer who reads this to take away is discipline around the capture-first habit. Console session logging on. Show tech captured before any clear command. NTP verified before you argue about routing. If you build those three habits, you will fix Catalyst 9200 Catalyst 9200 POE LLDP Negotiation Failure Boot Loop (and the next dozen Cisco failures you meet) in a fraction of the time it takes a less methodical engineer.

If you are working a P1 right now and stuck on this exact issue, my mailbox is at the byline below. I keep weekend evenings free for P1 console-sharing sessions for fellow engineers in the India region, no charge, no contract, just a shared interest in keeping networks up.