Link Down Event observed for an HBA yet fabric cables are connected

Products

• VMware vSphere ESXi
• VMware vSphere ESX 5.x
• VMware vSphere ESX 6.x
• VMware vSphere ESX 7.x
• VMware vSphere ESX 8.x
• VMware vSphere ESXi 5.0
• VMware vSphere ESXi 5.5
• VMware vSphere ESXi 8.0

Issue/Introduction

An Administrator observes a link state change from Up to Down in /var/log/vmkernel.log:

2025-04-11T21:55:19.764Z Wa(180) vmkwarning: cpu59:2098131)WARNING: lpfc: lpfc_mbx_cmpl_read_topology:3696: vmhba4  1305 Link Down Event x2 received Data: x2 x20 x800220 x0

Also, the link status for the HBA is reported as "link-down":

$ localcli storage core adapter list
HBA Name  Driver    Link State  UID                                   Capabilities         Description
--------  --------  ----------  ------------------------------------  -------------------  -----------
vmhba0    vmw_ahci  link-n/a    sata.vmhba0                                                (0000:00:11.5) Intel Corporation Lewisburg SATA AHCI Controller
vmhba1    vmw_ahci  link-n/a    sata.vmhba1                                                (0000:00:17.0) Intel Corporation Lewisburg SATA AHCI Controller
vmhba2    vmw_ahci  link-n/a    sata.vmhba2                                                (0000:3b:00.0) Marvell Technology Group Ltd. Dell BOSS-S1 Adapter
vmhba3    lpfc      link-up     fc.20000010########:10000010########  Second Level Lun ID  (0000:5e:00.0) Emulex Corporation Emulex LPe35000/LPe36000 Fibre Channel Adapter
vmhba4    lpfc      link-down   fc.20000010########:10000010########  Second Level Lun ID  (0000:5e:00.1) Emulex Corporation Emulex LPe35000/LPe36000 Fibre Channel Adapter
vmhba64   lpfc      link-up     fc.20000010########:10000010########                       (0000:5e:00.0) Emulex Corporation Emulex LPe35000/LPe36000 Fibre Channel Adapter
vmhba65   lpfc      link-down   fc.20000010########:10000010########                       (0000:5e:00.1) Emulex Corporation Emulex LPe35000/LPe36000 Fibre Channel Adapter

Cause

The link down event was caused by a faulty SFP. Port Fencing enabled on the fabric switch kept the port in a down state until the SFP can be replaced.

Resolution

Contact the fabric switch vendor for assistance. This issue is occurring due to a physical layer issue, specifically the SFP is faulty and needs to be replaced. This will correct the link state being reported. Port fencing allows a switch to monitor specific behaviors on the port and protect a switch by fencing the port when specified thresholds are exceeded (See Page 3: SAN Best Practices)