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

NTP issues


NTP (Network Time Protocol) allows machines to synchronize their time and date with a master server that is always considered to be accurate. There are several reasons why accurate time and date on the NetScaler are important:

  • Authentication protocols such as Kerberos and SAML rely on timestamps to check that the tokens issued are still valid. Authentication will fail if the time on the NetScaler is incorrect.

  • Caching relies on the time set on the NetScaler to determine if http objects are still valid.

  • When performing log analysis and trace analysis, it is important that the date and time correspond across different devices, to be able to match the times across various logs.

Note

Citrix article CTX120952 provides the necessary steps to configure NTP on NetScaler.

Before discussing troubleshooting, here's a quick summary of the steps that happen when a NetScaler is configured to synchronize its time with an NTP server:

  1. The NetScaler contacts the NTP Server and sets the original timestamp...