Verifying Layer 3 Connectivity; Symptoms - Cisco Nexus 9000 Series Troubleshooting Manual

Overview
• Use the show running-config spanning-tree command to verify that the Spanning Tree Protocol (STP)
• Use the show processes | include ER command to verify that nonessential Layer 2 processes are in the
• Use the show mac address-table dynamic vlan command to determine if learning or aging is occurring

Verifying Layer 3 Connectivity

Answer the following questions to verify Layer 3 connectivity:
• Have you configured a default gateway?
• Have you configured the same dynamic routing protocol parameters throughout your routing domain
• Are any IP access lists, filters, or route maps blocking route updates?
Use the following commands to verify your routing configuration:
• show ip arp
• show ip routing
See Troubleshooting Tools and Methodology, on page 93
Routing, on page 63

Symptoms

This document uses a symptom-based troubleshooting approach that allows you to diagnose and resolve your
Cisco NX-OS problems by comparing the symptoms that you observed in your network with the symptoms
listed in each chapter.
By comparing the symptoms in this publication to the symptoms that you observe in your own network, you
should be able to diagnose and correct software configuration issues and inoperable hardware components so
that the problems are resolved with minimal disruption to the network. Those problems and corrective actions
include the following:
• Identify key Cisco NX-OS troubleshooting tools.
• Obtain and analyze protocol traces using SPAN or Ethanalyzer on the CLI.
• Identify or rule out physical port issues.
• Identify or rule out switch module issues.
• Diagnose and correct Layer 2 issues.
• Diagnose and correct Layer 3 issues.
• Recover from switch upgrade failures.
• Obtain core dumps and other diagnostic data for use by Cisco TAC or your customer support
is configured the same on all devices in the network.
error state.
at each node.
or configured static routes?
for more information on troubleshooting Layer 3 issues.
representative.
to verify Layer 3 connectivity. See
Cisco Nexus 9000 Series NX-OS Troubleshooting Guide, Release 7.x
Verifying Layer 3 Connectivity
Troubleshooting
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