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

Troubleshooting Guidelines

By answering the questions in the following subsections, you can determine the paths that you need to follow and the components that you should investigate further.

Answer the following questions to determine the status of your installation:

• Is this a newly installed system or an existing installation? (It could be a new host, switch, or VLAN).
• Has the host ever been able to see the network?
• Are you trying to solve an existing application problem (too slow, high latency, excessively long response time) or did the problem show up recently?
• What changed in the configuration or in the overall infrastructure immediately before the applications started to have problems?

To discover a network problem, follow these steps:

Step 1 Gather information on problems in your system. See the “Gathering Information” section.

Step 2 Verify the Layer 2 connectivity. See the “Verifying Layer 2 Connectivity” section.

Step 3 Verify the configuration for your end devices (storage subsystems and servers).

Step 4 Verify end-to-end connectivity. See the “Verifying Layer 3 Connectivity” section.

Gathering Information

This section highlights the tools that are commonly used to troubleshoot problems within your network. These tools are a subset of what you might use to troubleshoot your specific problem.

Each chapter in this guide includes additional tools and commands that are specific to the symptoms and possible problems covered in that chapter.

You should also have an accurate topology of your network to help isolate problem areas.

Use the following commands and examine the outputs:

• show module
• show version
• show running-config
• show logging log
• show interface brief
• show vlan
• show accounting log
• show tech support svs

Note To use commands with the internal keyword, you must log in with the network-admin role.

Verifying Ports

Answer the following questions to verify ports:

• Is the media broken or damaged?
• Are you checking a virtual Ethernet port? If so, use the show interface brief command. The status should be up.
• Are you checking a physical Ethernet port? If so, you need to check it by looking at the server or by looking at an upstream switch.
• Check if the network adapters of the Virtual Supervisor Module (VSM) virtual machine (VM) are assigned the right port groups and if all of them are connected from vSphere Client.

Verifying Layer 2 Connectivity

Answer the following questions to verify Layer 2 connectivity:

• Are the necessary interfaces in the same VLANs?

Use the show vlan brief command. The status should be up.

Use the show port-profile command to check a port profile configuration.

Use the show interface brief command to check the status of a virtual Ethernet port or a physical Ethernet port.

Verifying Layer 3 Connectivity

Answer the following questions to verify Layer 3 connectivity:

• Have you configured a gateway of last resort?
• Are any IP access lists, filters, or route maps blocking route updates?

Use the ping or trace commands to verify connectivity. See the following for more information:

• Ping
• Traceroute

System Message Text

Message-text is a text string that describes the condition. This portion of the message might contain detailed information about the event, including terminal port numbers, network addresses, or addresses that correspond to locations in the system memory address space. Because the information in these variable fields changes from message to message, it is represented here by short strings enclosed in square brackets. A decimal number, for example, is represented as [dec].

Use this string to find the matching system message in the Cisco NX-OS System Messages Reference System Messages Reference.

Each system message is followed by an explanation and recommended action. The action may be as simple as “No action required.” It may involve a fix or a recommendation to contact technical support as shown in the following example:

next_gen_fcs_ip_38# show dc hosts vse

Internal IPG tags:

inside-trunk 1:1-50,

inside-trunk 2:2047-2096,

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

HOST NAME: 10.197.128.55

HOST IP: 10.197.128.55

VSE IP: 10.197.128.37

VSE UUID : 42193D34-FBB0-A6E9-4AAE-C4BC3043C013

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

Explanation VSE module inserted successfully on slot 3.

Recommended Action None. This is an information message. Use the show module command to verify the module in slot 3.

syslog Server Implementation

The syslog facility allows the Cisco Nexus 1000VE to send a copy of the message log to a host for more permanent storage. This feature can be useful if the logs need to be examined over a long period of time or when the Cisco Nexus 1000VE is not accessible.

This example demonstrates how to configure a Cisco Nexus 1000VE to use the syslog facility on a Solaris platform. Although a Solaris host is being used, the syslog configuration on all UNIX and Linux systems is very similar.

Syslog uses the concept of a facility to determine how it should be handled on the syslog server (the Solaris system in this example), and the message severity. Therefore, different message severities can be handled differently by the syslog server. They could be logged to different files or emailed to a particular user. Specifying a severity determines that all messages of that level and greater severity (lower number) will be acted upon.

Note The Cisco Nexus 1000VE messages should be logged to a different file from the standard syslog file so that they cannot be confused with other non-Cisco syslog messages. The logfile should not be located on the / file system, to prevent log messages from filling up the / file system.
Syslog Client: switch1
Syslog Server: 172.22.36.211 (Solaris)
Syslog facility: local1
Syslog severity: notifications (level 5, the default)
File to log Cisco Nexus 1000VE messages to: /var/adm/nxos_logs

To configure a syslog server, follow these steps:

Step 1 Configure the Cisco Nexus 1000VE.

Display the configuration.

Step 2 Configure the syslog server.

a. Modify /etc/syslog.conf to handle local1 messages. For Solaris, t at least one tab needs to be between the facility.severity and the action (/var/adm/nxos_logs).

b. Create the log file.

c. Restart the syslog.

d. Verify that the syslog has started.

Step 3 Test the syslog server by creating an event in the Cisco Nexus 1000VE. In this case, port e1/2 was bounced and the following was listed on the syslog server. Notice that the IP address of the switch is listed in brackets.

Viewing Logs

Use the following commands to access and view logs in the Cisco Nexus 1000VE.

Example 1-1 shows an example of the show logging command output.

Example 1-1 show logging Command