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It's not the Network! Ok, maybe it's the network...

Jason Rahm

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Top Stories by Jason Rahm

Virtualization Expo on Ulitzer If you haven’t yet downloaded the  BIG-IP LTM VE trial, I highly suggest you do.  It is a fully-functional LTM, rate-limited to 1Mbps throughput.  If you’re not familiar with virtualized environments, hopefully this blog will fill in some blanks for how to get started on the network front. Getting Started Before downloading your VE image, you need to choose what virtualization environment you’re installing into.  The supported options in the type 1 hypervisor are VMWare ESX version 4 and ESXi version 4.  For the type 2 hypervisor (requiring a host OS such as linux or Microsoft Windows) the supported option is VMWare Workstation 7, which offers a 30-day free trial that I recommend you give a shot, or for those with experience on VMWare player, that also will suffice if you are at version 3.  Note, however, that VMWare player is not supp... (more)

Mitigate Java Vulnerability with iRules

I got a request yesterday morning to asking if there was a way to drop HTTP requests if a certain number was referenced in the Accept-Language header.  The user referenced this post on Exploring Binary.  The number, 2.2250738585072012e-308, causes the Java runtime and compiler to go into an infinite loop when converting it to double-precision binary floating-point.  Not good.  Twitter is ablaze on the issue, and there is a good discussion thread on Hacker News as well.  So how do you stop it?  At first, this appeared to be a no-brainer, just copy that string and drop if found in that... (more)

The Wait Is Over: Edit Your iRules on Linux!

DevCentral has many rock star contributors.  Most are not affiliated officially with F5 Networks, or DevCentral for that matter, but there are several F5ers who believe in the community, and really believe in the F5 story.  One of those F5ers is Matt Cauthorn, or as you know him in the community, L4L7.  You may recognize Matt as the author of pyControl.  Well, not only did he provide this entrance to a better iControl experience, he has also delivered in a major way with his Vim plugin for editing iRules (utilizing pyControl of course to make those calls to BIG-IP).  I had toyed ... (more)

Host that Sorry Page on your BIG-IP!

It's not an uncommon problem trying to figure out where to plant that sorry page in the event your farm is down.  It's also not an uncommon solution to just use your BIG-IP to issue a text-only HTTP::respond.  It works, but it's not, how do you say, visually appealing?  You want to say sorry and mean it.  With pictures.  If you take a stroll through the iRules codeshare, you'll notice several solutions to this problem.  All of them work, with a variety of methods, but user kirkbauer's entry takes it to another level.  Kirk's sorry page irule generator (written in perl) takes all ... (more)

Let iRules Work Around that ASP.NET Padding Oracle Attack

Microsoft released advisory 2416728 on Friday after researchers Thai Duong and Juliano Rizzo demonstrated the attack on ASP.NET with their Padding Oracle Exploit Tool.  The attack itself preys on a bug in ASP.NET’s AES implementation, which you can read about over here at threatpost.  So what’s the reward for a successful attack?  It’s not going to allow the attacker to execute code or elevate rights, but it does all the attacker to read potentially sensitive data that could then be further used to compromise the system. The mitigation for this attack is to obfuscate the server ... (more)