Cisco Nexus 1000VE for VMware vSphere Troubleshooting Guide, Release 5.2(1)SV5(1.1)

Troubleshooting Tools

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This chapter describes the troubleshooting tools available for the Cisco Nexus 1000VE and includes the following topics:

• Commands
• Ping
• Traceroute
• Monitoring Processes and CPUs
• RADIUS
• Syslog

Commands

You use the command line interface (CLI) from a local console or remotely using a Telnet or Secure Shell SSH session. The CLI provides a command structure similar to Cisco NX-OS software, with context-sensitive help, show commands, multi-user support, and role-based access control.

Each feature has show commands that provide information about the feature configuration, status, and performance. Additionally, you can use the following commands for more information:

• show system — Provides information on system-level components, including cores, errors, and exceptions. Use the show system error-id command to find details on error codes:

Ping

The ping utility generates a series of echo packets to a destination across a TCP/IP internetwork. When the echo packets arrive at the destination, they are rerouted and sent back to the source. Using ping, you can verify connectivity and latency to a particular destination across an IP-routed network.

The ping utility allows you to ping a port or end device. By specifying the IPv4 address, you can send a series of frames to a target destination. Once these frames reach the target, they are looped back to the source and a time stamp is taken. Ping helps you to verify the connectivity and latency to destination.

Traceroute

Use traceroute to do the following:

• Trace the route followed by data traffic.
• Compute interswitch (hop-to-hop) latency.

Traceroute identifies the path taken on a hop-by-hop basis and includes a time stamp at each hop in both directions. You can use traceroute to test the connectivity of ports along the path between the generating switch and the switch closest to the destination.

Use the traceroute CLI command to access this feature.

If the destination cannot be reached, the path discovery starts, which traces the path up to the point of failure.

Monitoring Processes and CPUs

There CLI enables you to for monitor switch processes. CPU status, and utilization.

This section contains the following topics:

• Identifying the Running Processes and their States
• Displaying CPU Utilization
• Displaying CPU and Memory Information

Identifying the Running Processes and their States

Use the show processes command to identify the processes that are running and the status of each process. (See Example 2-1.) The command output includes the following:

• PID—Process ID.
• State —Process state.
• PC—Current program counter in hex format.
• Start_cnt—How many times a process has been started (or restarted).
• TTY—Terminal that controls the process. A “-” usually means a daemon is not running on any particular TTY.
• Process—Name of the process.

Process states are as follows:

• D—Uninterruptible sleep (usually I/O).
• R—Runnable (on run queue).
• S—Sleeping.
• T—Traced or stopped.
• Z—Defunct (“zombie”) process.
• NR—Not running.
• ER—Should be running but is currently not running.

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Note The ER state typically designates a process that has been restarted too many times, causing the system to classify it as faulty and disable it.

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Example 2-1 show processes Command

switch# show processes ?

cpu Show processes CPU Info

log Show information about process logs

memory Show processes Memory Info

 

switch# show processes

 

PID State PC Start_cnt TTY Process

----- ----- -------- ----------- ---- -------------

1 S b7f9e468 1 - init

2 S 0 1 - migration/0

3 S 0 1 - ksoftirqd/0

4 S 0 1 - desched/0

5 S 0 1 - migration/1

6 S 0 1 - ksoftirqd/1

7 S 0 1 - desched/1

8 S 0 1 - events/0

9 S 0 1 - events/1

10 S 0 1 - khelper

15 S 0 1 - kthread

24 S 0 1 - kacpid

101 S 0 1 - kblockd/0

102 S 0 1 - kblockd/1

115 S 0 1 - khubd

191 S 0 1 - pdflush

192 S 0 1 - pdflushn

...

 

RADIUS

RADIUS is a protocol used for the exchange of attributes or credentials between a head-end RADIUS server and a client device. These attributes relate to three classes of services:

• Authentication
• Authorization
• Accounting

Authentication refers to the authentication of users for access to a specific device. You can use RADIUS to manage user accounts for access to a Cisco Nexus 1000VE. When you try to log into a device, the Cisco Nexus 1000VE validates you with information from a central RADIUS server.

Authorization refers to the scope of access that you have once you have been authenticated. Assigned roles for users can be stored in a RADIUS server with a list of actual devices that the user should have access to. Once the user has been authenticated, the switch can then refer to the RADIUS server to determine the extent of access the user will have within the switch network.

Accounting refers to the log information that is kept for each management session in a switch. This information can be used to generate reports for troubleshooting purposes and user accountability. Accounting can be implemented locally or remotely (using RADIUS).

The following is an example of an accounting log entries:

Note The accounting log shows only the beginning and ending (start and stop) for each session.

Syslog

The system message logging software saves messages in a log file or directs the messages to other devices. This feature provides the following capabilities:

• Logging information for monitoring and troubleshooting.
• Selection of the types of logging information to be captured.
• Selection of the destination of the captured logging information.

Syslog allows you to store a chronological log of system messages locally or sent to a central syslog server. Syslog messages can also be sent to the console for immediate use. These messages can vary in detail depending on the configuration that you choose.

Syslog messages are categorized into seven severity levels from debug to critical events. You can limit the severity levels that are reported for specific services within the switch.

Log messages are not saved across system reboots. However, a maximum of 100 log messages with a severity level of critical and below (levels 0, 1, and 2) can logged to a local file or server.

Enabling Logging for Telnet or SSH

System logging messages are sent to the console based on the default or configured logging facility and severity values.

Users can disable logging to the console or enable logging to a given Telnet or SSH session.

• To disable console logging, use the no logging console command in global CONFIGURATION mode.
• To enable logging for Telnet or SSH, use the terminal monitor command in EXEC mode.

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Note Note: When logging to a console session is disabled or enabled, that state is applied to all future console sessions. If a user exits and logs in again to a new session, the state is preserved. However, when logging to a Telnet or SSH session is enabled or disabled, that state is applied only to that session. The state is not preserved after the user exits the session.

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The no logging console command shown in Example 2-4 does the following:

• Disables console logging
• Enabled by default

Example 2-4 no logging console Command

switch(config)# no logging console

 

The terminal monitor command shown in Example 2-5 does the following:

• Enables logging for Telnet or SSH
• Disabled by default

Example 2-5 terminal monitor Command

switch# terminal monitor

 

For more information about configuring syslog, see the Cisco Nexus 1000VE System Management Configuration Guide.