Port Types; Layer 2 Switching Problems; Verifying A Connection Between Vem Ports - Cisco Nexus 1000V Troubleshooting Manual

Layer 2 Switching Problems

S e n d d o c u m e n t c o m m e n t s t o n e x u s 1 k - d o c f e e d b a c k @ c i s c o . c o m .

Port Types

The following types of ports are available:
•
•
•
For more information about Layer 2 switching, see the Cisco Nexus 1000V Layer 2 Switching
Configuration Guide, Release 4.2(1)SV2(1.1).
Layer 2 Switching Problems
This section describes how to troubleshoot Layer 2 problems and lists troubleshooting commands. This
section includes the following topics:
•
•
•
•

Verifying a Connection Between VEM Ports

To verify a connection between two veth ports on a VEM, follow these steps:
On the VSM, enter the show vlan command to view the state of the VLANs associated with the port. If
Step 1
the VLAN associated with a port is not active, then the port may be down. In this case, you must create
the VLAN and activate it.
Step 2 To see the state of the port on the VSM, enter a show interface brief command.
Step 3 Enter the module vem module-number execute vemcmd show port command to display the ports that
are present on the VEM, their local interface indices, VLAN, type (physical or virtual), CBL state, port
mode, and port name.
The key things to look for in the output are:
•
•
•
•
•
Cisco Nexus 1000V Troubleshooting Guide, Release 4.2(1)SV2(2.1)
11-4
Veths (Virtual Ethernet Interfaces) can be associated with any one of the following:
VNICs of a Virtual Machine on the ESX Host.
–
VMKNICs of the ESX Host
–
VSWIFs of an ESX COS Host.
–
Eths (Physical Ethernet Interfaces) – correspond to the Physical NICs on the ESX Host.
Po (Port Channel Interfaces) – The physical NICs of an ESX Host can be bundled into a logical
interface. This logical bundle is referred to as a port channel interface.
Verifying a Connection Between VEM Ports, page 11-4
Verifying a Connection Between VEMs, page 11-5
Isolating Traffic Interruptions, page 11-6
Verifying Layer 2 Switching, page 11-7
State of the port.
CBL.
Mode.
Attached device name.
The LTL of the port you are trying to troubleshoot. It will help you identify the interface quickly in
other VEM commands where the interface name is not displayed.
Chapter 11 Layer 2 Switching
OL-28795-01