Untangle's Multi-Functional Firewall Software
I've been using Linux routers and Web filters for more than a decade. I've never seen a system with so many filtering features that is so easy to configure. I was particularly impressed with the Protocol Control module. Although not 100% accurate, it did a really good job of stopping traffic based on packet type. For example, in the first hour of school, Untangle found and blocked a student from running bittorrent on our network. The torrent traffic was running on a random port, but Untangle was able to identify and block the traffic. The system-wide Ad Blocker module also was nice, since blocking ads on Web sites helps kids focus on their work. (The moral ramifications of blocking Web ads in a school district are, of course, up to the reader, but the ad blocker works very well.)
The free Web filter (or “lite” version) is very basic. It includes a few categories and does not block SSL traffic. Although it might be sufficient for a home user trying to block accidental porn surfing, it certainly isn't robust enough for a K–12 school district. The premium Web filter, on the other hand, seems to be on par with other commercial Web filtering solutions. Pricing is based on concurrent users, but based on the pricing for 500 workstations, the cost was comparable or lower than other products. Because I was unable to authenticate Untangle with my user accounts, I can't attest to how fine-grained access control is, but the configuration appears to be adequate for tiered access. That's important for us, as staff and students have different access rights.
I've already mentioned the limited configuration options for user authentication. Unfortunately, that's not the only problem with authentication. Untangle works in transparent mode only. By that, I mean it intercepts traffic as it passes through the bridged network ports, but it doesn't act as a proxy. I find using a proxy (one that is configured on the browser and is assigned to connect via proxy server) is a very efficient way to manage Web filtering. Although transparent mode is convenient, it also breaks SSL connections, requiring some fancy hacking to block filtered SSL sites. Don't get me wrong, Untangle does a really great job of hacking, but if it had actual proxy support, it would be simpler to support SSL traffic. Plus, I wouldn't have to reconfigure 500 workstations that currently have proxy settings in the browser!
The only other frustration I had with Untangle was its system requirements. Although my single Xeon CPU is a few years old, with just the Web filter module active, my CPU was pegged at 100% usage most of the day. When I turned on the other modules, like Protocol Control, Ad Blocker, Spam Blocker and so on, my entire network slowed to a crawl. I do have a rather busy network, and I realize protocol analyzation is very CPU-intensive, but I was surprised at how quickly my 2.8GHz Xeon CPU became overloaded. Still, with enough horsepower, I fully expect my network would not slow down. Just be aware that Untangle's awesome features come at a CPU premium.
Untangle has an amazing number of features. Some of them seem a little redundant (like the Spyware Blocker and the Phish Blocker), but it's nicer to be overprotected rather than underprotected. The reports are searchable and quite visually appealing (Figure 3). I find myself looking at the daily reports that arrive in my e-mail inbox to look for trends and troublesome client computers. If authentication were a bit easier to configure, those same trends could be identified by user as well.
One of the best parts of being forced to use Untangle in a production environment is that I was able to identify its major weaknesses for my purposes very quickly. I'm happy to say that the company seemed very willing to hear my concerns, and the developers were given my feedback immediately. In fact, I wouldn't be surprised if some of my concerns are addressed by the time this review is printed. I'm always encouraged by a company that listens to criticism. Hopefully, that criticism will be put to good use in future editions of Untangle.
I'm always hesitant when companies provide a small portion of their product for free and charge for premium features. Thankfully with Untangle, the free offering is extremely generous and sufficient for what many users would want. The premium features are truly valuable, and the pricing is fair. There are some situations that make Untangle the wrong choice for your network, and unfortunately for now, I am in that situation. Until Untangle works out additional authentication schemes and provides direct proxying, I can't implement it as my main Web filter. I will admit, however, that even though I'm not using Untangle as my Web filter anymore, I did leave it in place to filter P2P traffic and block ads.
I'm very impressed with Untangle and would recommend it to others. With its very robust set of free features, many users won't need to pay in order to meet their needs. For more information and a free download, check out www.untangle.com.
Shawn Powers is the Associate Editor for Linux Journal. He's also the Gadget Guy for LinuxJournal.com, and he has an interesting collection of vintage Garfield coffee mugs. Don't let his silly hairdo fool you, he's a pretty ordinary guy and can be reached via e-mail at firstname.lastname@example.org. Or, swing by the #linuxjournal IRC channel on Freenode.net.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
- SUSE LLC's SUSE Manager
- My +1 Sword of Productivity
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Managing Linux Using Puppet
- Non-Linux FOSS: Caffeine!
- Doing for User Space What We Did for Kernel Space
- SuperTuxKart 0.9.2 Released
- Google's SwiftShader Released
- Parsing an RSS News Feed with a Bash Script
- SourceClear Open
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide