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

Jason Rahm

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Top Stories by Jason Rahm

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 header, right?  Well, there’s a catch.  A few actually.  This number can be represented in many ways: Decimal point placement => 0.00022250738585072012e-304 Leading Zeroes => 00000000002.2250738585072012e-308 Trailing Zeroes => 2.225073858507201200000e-308 Leading Zeroes in the Exponent => ... (more)

When Optimization Techniques Fail -- Why Testing is so Important

I'm always fascinated by the creative outlets people come up with when toying with iRules.  My favorite is still Joe's FTP Hunt the Wumpus, which he blogged about a while back (the code is here in the wiki).  The latest is a great entry from Lori this morning, giving you, the community, a handy dice roller.  After a careful read, a few thoughts came to mind, in no particular order. Wow, what a great way to collide two completely independent planets in the geek solar system. Role playing games take too much time, I just want to load up the console and shoot stuff.  Lots of stuff.... (more)

The ABCs of NSM - W is for Wireshark & Webmin

Welcome back for another episode of the ABC's of NSM.  What's NSM you say?  We'll go with Network and System Management, but you c ould throw Security in there as well.  We'll work our way through the alphabet over  the next several weeks looking at  tools and concepts along the way for all the administrators out     there.   By the way, you can thank Joe for the format & Don for the title  (I  couldn't for the life of me come up with one.) Today's letter W is a two-for-one special: Wireshark & Webmin. I'll start with Wireshark (formerly Ethereal), which is a cross-platform open... (more)

iRules Insight - HTTP Event Order

I'm a visual learner.  You know this about me.  I've said as much in earlier posts (Me Caveman, Need Picture).  So it should come as no surprise that I'll be highlighting a picture here.  A picture is worth a thous...yada yada yada, you get it.  I see many drawings, all of which are purposed to convey some type of information.  This, however, is a visual treasure chest building on the event ordering goodness discussed by Colin a while back that hones in on the flow of data through the iRules events specific to the HTTP protocol.  If you develop iRules for HTTP traffic, you need t... (more)

Live from Microsoft Tech Ed: Final Day

So I guess I’m on the even days plan here at Tech Ed, today being the fourth and final day of Tech Ed…  Yesterday I got the chance to walk around the exhibitor hall and take a look at the exciting offerings on the floor.  Microsoft had three very large sections with breakout booths for all their product offerings.  I stopped and chatted with a few experts in the Server 2008 R2 virtualization offerings, and watched a couple System Center demos as well.  Speaking of System Center, did you know F5 has a management pack for System Center?  I talked to several booth visitors yesterday... (more)