Book Image

Troubleshooting NetScaler

By : Raghu Varma Tirumalaraju
Book Image

Troubleshooting NetScaler

By: Raghu Varma Tirumalaraju

Overview of this book

NetScaler is a high performance Application Delivery Controller (ADC). Making the most of it requires knowledge that straddles the application and networking worlds. As an ADC owner you will also likely be the first person to be solicited when your business applications fail. You will need to be quick in identifying if the problem is with the application, the server, the network, or NetScaler itself. This book provides you with the vital troubleshooting knowledge needed to act fast when issues happen. It gives you a thorough understanding of the NetScaler layout, how it integrates with the network, and what issues to expect when working with the traffic management, authentication, NetScaler Gateway and application firewall features. We will also look at what information to seek out in the logs, how to use tracing, and explore utilities that exist on NetScaler to help you find the root cause of your issues.
Table of Contents (17 chapters)
Troubleshooting NetScaler
Credits
Notice
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Using nstrace to capture a packet trace


While the logs on the NetScaler help build a picture of what happened, it is oftentimes necessary to delve deeper and identify what device is responsible for the issue (for example, is it the Server, NetScaler, or the Network?). Examining a network trace taken on the NetScaler helps identify the next steps by narrowing down the focus area.

Steps to run a trace

You can take a trace using the GUI, the CLI, or the shell. The recommended way is to do this over the GUI, which provides easy dropdown-based filtering choices as well as an option to download the trace once it's captured.

To take a trace from the GUI, use the start new trace option in the Diagnostics section.

Let's take a look at some general recommendations for running a trace.

  • Always attempt to capture simultaneous traces to start with—on the client machine, NetScaler and server.

  • Run the trace with a packet size of 0 unless the packets you are looking for are really small, especially SSL traces...