Everyone has surely (don’t call me Shirley!) at least been exposed to THE CLOUD by now.  Whether it’s the—I’ll go with interesting—“to the cloud!” commercials or down in the nuts and bolts of hypervisors and programmatic interfaces for... Read more

Introduction Virtually every dynamic site on the Internet these days makes use of a CAPTCHA in some fashion. A CAPTCHA is used to verify that a human is driving the interaction with a particular  function on a site. A CAPTCHA in its simples... Read more

Introduction Earlier this year Google released their time-based one-time password (TOTP) solution named Google Authenticator. A TOTP is a single-use code with a finite lifetime that can be calculated by two parties (client and server) using ... Read more

iApps, introduced in v11, have a primary function in controlling the object creation and management for an application delivered by BIG-IP. As discussed previously, however, anything that can be accomplished in TMSH can be done in an iApp, so wha... Read more

Introduction: Whenever customers expose their internal resources on the Web using VPNs or SSL VPNS there is still some concern over what type of traffic comes through the connection. In order to assist with these concerns we can provide a combine... Read more

As we hurtle forward through the information age we continue to find ourselves increasingly dependant on the applications upon which we rely. Whether it's your favorite iPhone app or the tools that allow you to do your job, the application... Read more

One time passwords, or OTP, are used (as the name indicates) for a single session or transaction.  The plus side is a more secure deployment, the downside is two-fold—first, most solutions involve a token system, which is costly i... Read more

iRule performance has long been a question our users have asked about.  We get questions all the time about how to determine what impact a specific iRule has on the normal operation of the BIG-IP’s they are running on.  The question is a... Read more

I started working on an administrator control panel for my previous Small URL Generator Tech Tip (part 1 and part 2) and realized that we probably didn’t want to make our Small URL statistics and controls viewable by everyone. That led me to make... Read more

Introduction The LTM VE is a lifesaver when it comes to developing applications that use the iControl interface, or for development of iRules. My main (personal) use of it so far is the development of applications that use the iControl interface... Read more

With the BIG-IP GTM and 3-DNS products, location-based service has existed in the form of topology-based load balancing.  The possibilities grow exponentially in v10.1, as you now have the capabilities in GTM and LTM.  In this tech tip... Read more

LDAP is one of the most widely used authentication protocols around today. There are plenty of others, but LDAP is undeniably one of the big ones. It comes as no surprise then that we often hear different questions about using F5 technology with... Read more

SSL encryption as a means of security on the web isn't a new concept. We've talked about it here on DevCentral many times, and it's as pedestrian a concept as a corndog on the boardwalk to most internet users. We've talked about... Read more

SSL encryption on the web is not a new concept to the general population of the internet. Those of us that frequent many websites per week (day, hour, minute, etc.) are quite used to making use of SSL encryption for security purposes. It's an... Read more

Data Groups can be useful when writing iRules.  A data group is simply a group of related elements, such as a set of IP addresses, URI paths, or document extensions. When used in conjuction with the matchclass or findclass commands, you... Read more

What is RADIUS? “Remote Authentication Dial In User Service” or RADIUS is a very mature and widely implemented protocol for exchanging ”Triple A” or “Authentication, Authorization and Accounting” information. RADIUS is a relatively simple,... Read more

iRules are the internal scripting language of the BIG-IP and can be used to attain full control of traffic flowing through your network.  But, did you know that you can automate the management of iRules across your Virtual Servers with... Read more

RADIUS is very popular authentication method that is being widely used in amongst some of the top service providers around the world, not to mention in deployments ranging from enterprise corporate environments to clustered mail systems and back.... Read more

Customers frequently ask if they can condition their iRule logic on information retrieved real-time from an external source.  In most cases, you really can't. Most external calls are blocked If an external call were to take place inside... Read more

Path Traversal is an attempt to access files and/or directories stored outside web root folder. If successful this could allow malicious users to view content they were not intended to see, execute programs that have lax permissions and were... Read more

A fun, but not well known, feature on BIG-IP is the Statistics Profile. This tech tip is the second in a series on how the Statistics Profile and iRules, when working together, can save time, productivity, and your sleep! The Scenario: Imagine... Read more

As the applications being driven by webservers become more and more complex, Applications Developers are always looking for ways to increase efficiency or do away with unneeded processing time. One of the ways that I believe that Applications can... Read more

When building many enterprise web-based applications, security must be taken seriously. iRules provide powerful capabilities for influencing security decisions when processing for your web services and applications. This is a rule for requiring a... Read more