Citrix Continues to Virtualize Appliances

Five or six years ago, when Citrix first announced the Citrix Access Gateway appliance, I remember scratching my head and thinking, “Wait a minute, Citrix is in the software business. Why in the world do they want to start selling hardware, with all of the warranty, repair, and support issues that come along with being a hardware manufacturer?” The answer, of course, was that in order to build out the complete Application Delivery solution they envisioned, they needed components that, at the time, couldn’t be delivered using software alone.

But the world turns, and time moves on, and today Citrix has a world-class virtualization platform that runs on off-the-shelf server hardware that is itself mind-bogglingly powerful compared to what was available five or six years ago. So it makes all the sense in the world for Citrix to turn all of those hardware devices into virtual appliances as quickly as they can.

Yesterday, they formally announced virtualized versions of both the Access Gateway and the Branch Repeater. We’ll get to the virtual Branch Repeater in another post, because we’ll have our hands full in this one just covering the things you need to know about the Access Gateway VPX.

First, you need to know that the Access Gateway VPX is fundamentally a virtualized version of the 2010 CAG Appliance – with some exceptions that we’ll get into in a moment. You can download it and use XenCenter to import it directly into your XenServer environment. The cost is only $995 (compared to $3,500 for the 2010 hardware appliance), with an ongoing Subscription Advantage cost of $129/year. Here’s where it gets cool:

  • It was difficult to come up with a good solution for redundancy and automatic failover with the 2010 appliance. Unless you wanted to put a load-balancer in front of it (and if you’re going to do that, you may as well just buy a NetScaler in the first place), redundancy depended on putting primary and secondary appliance URLs or IP addresses into the CAG client. And that did you no good at all if you were trying to run it in “CSG-replacement mode” just to provide secure Web access to a XenApp farm. But the VPX virtual appliance fully supports Live Motion, XenServer HA, and NIC bonding. So the VPX doesn’t have to be redundant, because the underlying XenServer infrastructure can provide the resilience you need.
  • If you were using a 2010 appliance, and wanted to use “SmartAccess,” you had to stand up a separate “Advanced Access Control” Web server in your protected network. Obviously, that added to the cost and complexity of the solution. The VPX appliance, on the other hand, supports SmartAccess policies directly.

    Edit July 27, 2010: Not sure now where I originally picked up this information, but it is incorrect. An Advanced Access Control Web server is still required to enable SmartAccess policies with the Access Gateway VPX.

NOTE: SmartAccess, in case you’re not familiar with the term, allows you to control, at a very granular level, what applications and information a user can access, and what they can do with that information, based on the access scenario. The same user, presenting the same authentication credentials, might get a totally different level of access depending on whether s/he is connecting from inside the corporate network, from outside the network using a company-owned laptop, from home using a personal PC, or from a hotel business center using a totally untrusted device. For more information on how SmartAccess works and why it’s cool, check out this video from Citrix TV:


  • The VPX appliance fully supports the latest generation of the Citrix Receiver, and works with Dazzle and the Merchandising Server.
  • You no longer need to buy VPN client licenses to run it in “CSG replacement” mode. This is a biggie. Citrix made it clear some time ago that they would not be putting any more development time and effort into enhancing the software “Citrix Secure Gateway.” But the CSG just wouldn’t die, for one simple reason: it’s free. If you own XenApp or XenDesktop licenses with current Subscription Advantage, you’ve got the rights to use the CSG software, and your only cost is a server to run it on…and that’s pretty low in today’s virtual world. Yes, it could be argued that the CAG appliance was somewhat more secure, since it ran on a hardened Linux-derived kernel. But it cost $3,500 plus roughly $100 per concurrent user. Hmmm… CSG, free, CAG appliance, several thousand dollars. That was an easy decision for a lot of users.

    Co-incident with the release of the VPX appliance, Citrix is announcing that they’re eliminating the Access Gateway Standard User Licenses. They will no longer be sold as of June 30. Instead, when you buy an Access Gateway (physical or virtual), you get a “platform license” that entitles you to use it to secure access to a XenApp or XenDesktop farm (i.e., what’s generally referred to as “CSG Replacement Mode”) at no additional charge. So now the equation is: CSG, free, but I’ve got to put it on a server, and if it’s a Windows Server, the OS is going to cost me $700 – $800 or so. CAG VPX, $995, but I import it directly into my XenServer infrastructure and don’t have to pay for anything else unless I want the advanced access functionality. Suddenly the value proposition looks a lot more attractive.

  • Speaking of the advanced access functionality, Citrix has made some licensing changes there as well. The Access Gateway Universal licensing model has been reduced from three tiers to two, and the prices have been lowered. So now, if you didn’t purchase the XenApp or XenDesktop Platinum Editions (which include Access Gateway Universal licenses), you can purchase the Access Gateway Universal licenses separately for $100/concurrent user in quantities up to 2,500, and $50/concurrent user for 2,500+ users.

What’s the down side? Well, I’m not sure there is one. The VPX appliance isn’t going to work well as a general-purpose SSL/VPN for thousands of concurrent users, but then neither did the 2010 hardware appliance. So if that’s what you need, or if you need the high-end enterprise features like Global Server Load Balancing to enable transparent failover to a Disaster Recovery site, then we need to have a conversation about NetScalers. But for basic CSG-like functionality, or a SmartAccess deployment for a few hundred concurrent users, the virtual appliance looks pretty darned attractive to me.

For more information on the Access Gateway VPX, including a demo of just how easy it is to import it into your XenServer environment and get it running, check out the following video from Citrix TV:

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