Which cyphers to use on a Citrix ADC /NetScaler?


latest update: May 5th 2021 Recently I found myself in a discussion with another Citrix architect about the number of cyphers needed. I had added as little as fife cyphers to a cypher group. He thought this is not enough. Why should we have many cyphers into a cypher group? To be honest, I don’t understand. It may look flexible, feature-rich and mighty. Customers may get impressed...

A simple way for a Citrix ADC (NetScaler) to respond with a 404 not found


I am a big fan of cheating if it comes to security. Giving wrong answers to questions may be misleading and will direct attackers into the wrong direction. This will cost time and, at the same time, rise the risk of being caught red-handed. If someone attacks a website, he has to be discrete and fast. Discrete to not get trapped, quick to be long gone in case the owner learns about the attack. So...

A quick way to expand performance on Citrix (NetScaler) Gateways


This is Corona time, and Corona drives virtualization like nothing else did before. I recently had to fix issues with remote access. Usually, it would have to handle round about 1,500 users, but now, the number of users increased to 15,00, so ten times as much. The existing MPX-11500 could not handle all these connections, latency was way to high. Our customer needed a quick resolution, as every...

Using Geo-Location for policies and logging in Citrix NetScaler ADC


Last update: May 8th 2023   There are several use cases for geo-location information in Citrix ADC / NetScaler. It may be helpful with WAF logs. I am European, I won’t spend much time on a positive, if the log comes from North Korea, but I would consider it to be a “false positive”, if it comes from Germany, Italy or Sweden. Even though I would not consider it to be secure...

Are there Syslog events coming from partitions?


© Wikipedia, Creufop There seems to be no way to log events inside partitions, even though there are settings for logging and configuration seems to be right. They are exactly the same as in default partition. Syslog server is, so the local machine. Everything seems to be perfect. But /var/partitions/<partitionname>/log will remain empty. Why? Well, the syslog-server is

Creating Certificates for Citrix ADC (NetScaler)


The way we create certificates has not changed significantly over the years. Only the wizard is subject to a certain change. This blog is based on Citrix ADC 13, elder versions don’t differ significantly. The following steps are necessary to create a certificate: Generate the key pair Create the certificate-signing request Generate the certificate (either using Citrix ADC /...

I got rewarded CTA!


Two weeks ago Citrix sent me an email saying that they had awarded me as CTA, a Citrix Technology Advocate. It had been released today. It is a great honour to me! I am one of very few Citrix technicians worldwide who have received this award, the only one in Austria. I also known many of the existing CTAs, and they are all people that I appreciate, some of whom I am friends with, people who I...

Creating a Citrix ADC / NetScaler Test environment #2


last update: May 5th 2020 Almost two years ago I created a test website for Citrix NetScaler. The product is now called Citrix ADC. It had been a set of files, both, for both, Linux and Windows. It allowed you to create a test environment to test load-balancing solutions, content switching and more. My test web page is very similar to the pages, Citrix Educations use in CNS-220 and the first 3...

How to recover a Citrix ADC/NetScaler VPX from CVE-2019-19781 (both on Hypervisor and on SDX)


last update: March 2nd 2020 Well, there are many guides. So why do I write a blog about it? Just to have one more? Bull shit! The truth is: I don’t like them at all! What’s wrong about all these guides? They all focus on how to remove malware currently installed on our Citrix ADCs (NetScalers). And, to be honest, it does not make the least little bit of sense. How can you ever be 100%...

How to start a Citrix ADC / NetScaler WAF Project, Part 4: Start URLs


This is the forth part of this blog. Part Part 1 2 3 4 5 Click here to see how to start your WAF project StartURLs are a powerful tool to protect a web server. Probably, creating StartURLs will be the first thing you need to do. There are two ways to deal with it: Learning or doing. Learning Learning does not mean, you learn, instead Citrix ADC / NetScaler learns about the application. There is...

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