One of the main concerns that my large customers have is that the Citrix Gateway could fall victim to a DOS or DDOS attack. Linked to this, of course, is the concern that – after a successful attack – it might be possible to bypass authentication or compromise the gateway or the appliance. We have to distinguish between attacks that happen before and those that happen after...
DDOS protection using Citrix NetScaler, 2nd part
Yesterday I published a blog about DDOS- protection. I used the Citrix NetScaler AppQoE feature to do so. That’s nice, but not enough. I still could beat my server to a pulp easily. Just 10 clients launching a DDOS attack using HULK had been enough. I can’t throttle down the number of users to just 10! WTF? Basically AppQoE will just limit the number of users (actually it’s the...
Protect a DNS server using a Citrix NetScaler
Recently I found out: DNS is a big bandwidth waster on my internet connection. Strange, isn’t it? DNS? So I started a network trace on my firewall: someone is abusing one of my DNS servers. I guess it’s a kind of malware using my DNS server, but I am not really sure. The domain was X99MOYU.NET belonging to a Chinese company called ZhuHai NaiSiNiKe.. Content of the website is not...