Cisco Cisco Nexus 1000V Switch Troubleshooting Guide
Using vemlog to debug Nexus 1000v problems
Document ID: 115761
Contributed by Christopher Brown, Cisco TAC Engineer.
Jan 15, 2013
Jan 15, 2013
Contents
Introduction
Prerequisites
Requirements
Components Used
Conventions
Running vemlog commands
Vemlog debugging levels
Step 1: Clearing Current Capture settings
Step 2: Setting the vemlog capture parameters
Step 3: Viewing the output
Step 4: Restoring vemlog to normal logging levels
Related Information
Prerequisites
Requirements
Components Used
Conventions
Running vemlog commands
Vemlog debugging levels
Step 1: Clearing Current Capture settings
Step 2: Setting the vemlog capture parameters
Step 3: Viewing the output
Step 4: Restoring vemlog to normal logging levels
Related Information
Introduction
The Virtual Ethernet Module (VEM) portion of the Nexus 1000v has built−in debug commands that you can
use to assist in troubleshooting. These vemlog commands allow you insight to what certain processes of the
VEM are doing, what commands they are sending out, and what sort of response they are receiving. For
example, you might use them in these situations:
use to assist in troubleshooting. These vemlog commands allow you insight to what certain processes of the
VEM are doing, what commands they are sending out, and what sort of response they are receiving. For
example, you might use them in these situations:
A LACP port−channel is not coming up between the Nexus 1000v and the upstream switch. You
would use a combination of vemlog on the host and debug on the upstream switch to narrow
down the problem.
would use a combination of vemlog on the host and debug on the upstream switch to narrow
down the problem.
•
QoS is not working correctly and you want to verify that the VEM is setting the values correctly.
•
You want to see the changes to the VSM−VEM communication.
•
The most common use case for running these commands is debugging LACP. Using the debug module
"sflacp" and "debug lacp" on the upstream switch you can detect which device is malfunctioning, or if the link
between the two devices is dropping the LACP BPDUs.
"sflacp" and "debug lacp" on the upstream switch you can detect which device is malfunctioning, or if the link
between the two devices is dropping the LACP BPDUs.
The default levels usually have enough information so the log can be collected and analyzed without turning
on additional debugs.
on additional debugs.
Prerequisites
Requirements
There are no specific requirements for this document.
Components Used
This document is not restricted to specific software and hardware versions.