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Introduction to Cisco NX-OS

Chapter Description

This chapter provides an introduction and overview of NX-OS and a comparison between traditional IOS and NX-OS configurations and terminology.


The troubleshooting sections introduce basic concepts, methodology, and general troubleshooting guidelines for problems that might occur when configuring and using Cisco NX-OS.

show Commands

Table 1-2 lists sample EXEC commands showing the differences between IOS and NX-OS.

Table 1-2. Sample EXEC Commands Showing the Differences Between IOS and NX-OS




Displays the running configuration

show running-config

show running-config

Displays the startup configuration

show startup-config

show startup-config

Displays the status of a specified port-channel interface

show etherchannel #

show port channel #

Displays the current boot variables

show boot

show boot

Displays all environmental parameters

show environment

show environment

Displays the percentage of fabric utilized per module

show fabric utilization

show hardware fabric-utilization [detail]

Displays the supervisors high-availability status

show redundancy

show system redundancy status

Displays CPU and memory usage data

show process cpu

show system resources

Displays specific VRF information

show ip vrf name

show vrf name

debug Commands

Cisco NX-OS supports an extensive debugging feature set for actively troubleshooting a network. Using the CLI, you can enable debugging modes for each feature and view a real-time updated activity log of the control protocol exchanges. Each log entry has a timestamp and is listed chronologically. You can limit access to the debug feature through the CLI roles mechanism to partition access on a per-role basis. Although the debug commands show real-time information, you can use the show commands to list historical and real-time information.

By using the ? option, you can see the options that are available for any feature. A log entry is created for each entered command in addition to the actual debug output. The debug output shows a timestamped account of the activity that occurred between the local device and other adjacent devices.

You can use the debug facility to track events, internal messages, and protocol errors. However, you should be careful when using the debug utility in a production environment because some options might prevent access to the device by generating too many messages to the console or creating CPU-intensive events that could seriously affect network performance.

You can filter out unwanted debug information by using the debug-filter command. The debug-filter command enables you to limit the debug information produced by related debug commands.

Example 1-16 limits EIGRP hello packet debug information to Ethernet interface 1/1.

Example 1-16. Filtering debug Information

switch# debug-filter ip eigrp interface ethernet 1/1
switch# debug eigrp packets hello</code>