There is one thing different about a Citrix ADC WAF (Web Application Firewall) compared to most other features in Citrix ADC: It will affect your whole ADC deployment as soon as you turn it on. It you would, for example, turn on rewriting feature (enable feature RW), it would probably add a microsecond or two to packet processing, but apart from this not affect anything, as there are no policies...
I love doing whiteboarding sessions. I always do it during training, and I also did some at home and put these on YouTube. This is a list of Videos I did: My first Video was about setting up a Citrix ADC (Citrix NetScaler). It was a blended video, some parts clicking into Citrix NetScaler ADC, some parts white-boarding My second Video was about basic Load-balancing on Citrix ADC (Citrix...
last update: October 2nd 2018 This is the second part of debugging logon. The first one, a network trace about LDAP, may be found here. Citrix ADC / NetScaler logs all events related to AAA (authentication, authorization, auditing) to /tmp/aaad.debug You need to be nsroot or superuser to successfully log on to the BSD shell. This is a requirement to change to BSD shell. Change to the /tmp...
last update: November 3rd 2020 This is the first part of debugging logon problems. The second one, an explanation of aaad.debug log, may be found here. Recently I had to debug LDAP authentication on Citrix ADC / NetScaler and I started digging deeper. I wanted to know how LDAP authentication really works, so I did what I always do in a case like that: I started with a network trace. Attention: in...
Last update: Sept. 26 2018 I recently had to set languages, using my Citrix ADC (NetScaler), for a website. My customer has several similar web-pages in different subdirectories. Naming scheme is like this: for English for German … There is currently a total of 12 languages. There had been several requirements, and I had to create a set of responder policies to meet the requirements: if an...
Last update: 12/2020
This blog post had been very outdated, there are better ones. Continue reading here!
Recently I had several requests related to NITRO. NITRO is Citrix NetScaler’s API. Any device may communicate to a NetScaler using NITRO. Even a browser! Citrix exposes several settings and counters and even allows changes. NITRO is the central source for scripting NetScalers. I, being rather an administrator than a programmer, am not that much interested in using NITRO with C++/C#, Java...
How to protect your cookies using Citrix NetScaler Remark: Citrix ADC (NetScaler) firmware version 13 contains cookie theft protection. I recently did a web application firewall (WAF) project for a big company owning and hosting hundreds of websites. They did several penetration tests. One of them focussed on cookies. Citrix NetScaler did a great job protecting cookies, cookie tampering was...
Last update: Nov 21th, 2018 tested using firmware 11.1 If you read about slowloris, you always read about NetScaler doing a great job. Tests in our lab environment show: NetScaler will successfully block these attacks. And there is hardly anything we have to do about it: It’s built into the system. Great news indeed! The only thing we have to do is reduce client idle timeout to a lower...
All of us are always a bit shy looking at Citrix Synergy: What will it bring? Well, this time, Citrix comes up with brand new names for all products. It’s the first time Citrix is renaming the product. Until now the mane resisted all renaming by marketing departement. Citrix aquired NetScaler back in 2005. The original company “NetScaler” was founded by Michel K Susai in 1997...