Cisco Cisco Nexus 7000 4-Slot Switch Troubleshooting Guide

Troubleshoot Xbar Sync Failures on a Nexus 7000
Series Switch

Document ID: 118970

Contributed by Abhishek Soni, Cisco TAC Engineer.
Jun 17, 2015

Contents

Introduction
Prerequisites
Requirements
Components Used
Problem
Solution
Related Information

Introduction

This document describes how to identify a faulty crossbar (Xbar) when a module is down due to an Xbar sync
failure on a Cisco Nexus 7000 Series switch. The troubleshooting procedure for this problem involves the
collection of data, data analysis, and an elimination process in order to isolate the problem component.

Prerequisites

Requirements

Cisco recommends that you have knowledge of the Cisco Nexus Operating System (NX-OS) CLI.

Components Used

The information in this document is based on the Cisco Nexus 7000 Series switch that runs NX-OS Version
6.1(2), but it can also work with any NX-OS version.

The information in this document was created from the devices in a specific lab environment. All of the
devices used in this document started with a cleared (default) configuration. If your network is live, make sure
that you understand the potential impact of any command.

Problem

The N7K-F248XP-25E module is down due to an Xbar sync failure upon module boot. When the module was
inserted into Slot 1 on the chasis, it powered down. This can occur due to one of these reasons:

Bad module

•

Bad Xbar

•

Bad or bent pin on the backplane

•