Address ACI fault F1394: interface-physical-down

Introduction

This document describes steps for remediation of ACI fault F1394: interface-physical-down.

Background Information

A Fabric port is an interface which connects between an ACI mode Leaf switch and Spine switch. Fault code F1394 occurs when any such fabric port goes down.

code : F1394
cause : interface-physical-down
descr : Port is down, reason:linkNotConnected(connected), used by:Fabric
dn : topology/pod-x/node-xxx/sys/phys-[eth1/x]/phys/fault-F1394
rule : ethpm-if-port-down-fabric

If there are no redundant paths, this event can cause an outage or reduced performance in the fabric.

Intersight Connected ACI Fabrics

This fault is actively monitored as part of Proactive ACI Engagements.

If you have an Intersight connected ACI fabric, a Service Request was generated on your behalf to indicate that instances of this fault were found within your Intersight Connected ACI fabric.

Quick Start to Address Fault

1. Validate that both ends of the links are enabled. All ports are enabled by default
2. Validate that the interfaces in question were not manually blacklisted
3. Proceed with Layer 1 Troubleshooting and Isolation

Detailed Steps to Address Fault

Validate Both Ports are Enabled

Via the APIC GUI

1. Navigate to Fabric > Inventory > Pod <#> > <nodeId> > Interfaces > Physical Interfaces > ifId
2. If not enabled: right-click and select ‘Enable’

Via the Switch CLI

1. show interface <ifId>
2. show interface <ifId> status
3. show interface <ifId> transceiver
4. show interface <ifId> transceiver detail. If transceiver supports Digital Optical monitoring(DOM) and if DOM policy is enabled, light levels can be checked.

Validate Both Ports have not been Disabled/Blocklisted

Via the APIC GUI

1. Navigate to Fabric > Inventory > Disabled Interfaces and Decommissioned Switches
2. If present: right-click and ‘Delete’

Perform Layer 1 troubleshooting

1. Validate transceiver/leaf/version compatibility using the Cisco Optics-to-Device Compatibility Matrix
2. Check for interface status, transceiver and Digital Optical Monitoring(DOM) details from switch CLI using  commands listed under 1b above
3. Reseat transceivers or DAC cable at both ends
4. Check for potential issues fiber length and patch-panel if in path.
5. Check/swap fiber
6. Check/swap transceivers or DAC cable
7. Move interface on Leaf, Spine one at a time to see if issue follows transceiver/DAC/cable or stays with specific interfaces