Cisco Cisco UCS B440 M1 High-Performance Blade Server Guia De Resolução De Problemas
Contents
Introduction
Prerequisites
Requirements
Background Information
Indications you may have hit a CRC related defect
Commands which can be used to verify 'Eye Height'
Defects
Fabric Interconnect defects
IOM and Adapter defects
C-Series defects
Nexus 5500 defects
Workarounds/Mitigation
Introduction
This document outlines key software defects which can cause corrupt data frames, as identified by
interface Cyclic Redundancy Check (CRC) or FCS (Frame Check Sequence) error counters, to be
injected into a UCS Fabric
interface Cyclic Redundancy Check (CRC) or FCS (Frame Check Sequence) error counters, to be
injected into a UCS Fabric
Prerequisites
Requirements
This document does not describe how to isolate the point of CRC injection.
Frame and Packet Loss to identify the source of unstomped CRC errors within the UCS Fabric
and/or upstream switches.
and/or upstream switches.
While the document is intended for FlexPod deployments, the section mentioned is applicable for
non-FlexPod UCS environments.
non-FlexPod UCS environments.
Background Information
In a UCS environment, CRC errors can be highly impacting. Isolating and mitigating the cause of
such errors should be treated with high priority.
such errors should be treated with high priority.
Depending on the point at which the issue occurs, the impact can extend to multiple chassis and
impact both Ethernet and Storage connectivity.
impact both Ethernet and Storage connectivity.
While physical component failure (especially cable and SFP) is the most frequent cause, there is
an increase in number of software defects which can also cause CRC errors.
an increase in number of software defects which can also cause CRC errors.
These defects cause low signal strength between various components, leading to corrupt frames.