My Mac is bypassing a website filter... How can I stop it?

Question

I am a computer technician at our local high school. Right now, the school has about 800 Dell computers, but we are planning on introducing a few Macintosh labs within the next school year.
Since they lack educational value, the school district's director of technology (my boss) has a web filter (Deep Nine) that blocks myspace, facebook, youtube, proxy sites, and other similar sites.
Myspace is blocked via a keyword filter, any page containing the word "myspace" in the url, or in the document a set number of times, is automatically blocked. The other sites are simply blocked by URL. This filter works perfectly on our Dells, no one can access Myspace, Facebook, Proxies, etc.
I brought my Macbook to work today, plugged it into the network, and logged onto the internet. I noticed instantly that my homepage (Facebook) loaded without being blocked at all. Curious, I tested myspace and youtube, and I could get on youtube fine, but myspace remained blocked.
I checked on the Dell next to me, and all those sites will still being filtered and blocked. Yet my Macbook was able to access them without issue. So it would appear that my Macbook has some mystic ability to bypass the web address filter, but it can not bypass the keyword filter.
I do not have any proxies configured. My Macbook connects to the network (and thus, the internet) the same exact way the other computers within the school do, with the exception of the other computers being within Active Directory.
I need to find out if it is an issue with the Mac or with our Filter. I don't have any other Macs available to test with (Our only other Mac in the school is our DHCP server, and we do not use servers as "lab rat" computers).
Has anyone had any similar issues with this? Or does anyone know of any way I can diagnose this with only one Mac and only one Filter?
Specs: OS 10.5.5, Safari 3.1.2, wired networking.
Message was edited by: Joey Hogan
Message was edited by: Joey Hogan

Answer 1

The DeepNines product works well and does much more than a simple URL filter. The problem lies entirely in your district setup and not in their product. If you're not using a proxy filter, then you have all access and routes designed to head out on typical port 80 traffic to your isp and ultimately the internet hence no proxy configs. The filter is integrated with LDAP accounts at each of your locations to tell it which users and groups are to get filtered at what level. That tie in is what breaks down who goes where. If you introduce new macs onto the network and they have not been configured to work with the DN appliance and are going out unfiltered... then there are 2 problems here. #1 is that you have computers attaching to the network, receiving leases and doing what they want. Use DHCP reservations or a whitelist to control who gets on your network. #2 is that your DeepNines filter has not been set to failover to BLOCK. Instead, it's allowing unknown users to bypass freely simply because it doesn't recognize their group/account. And Orange, stop slamming the company. They are a smaller business that has taken a much better approach to filtering than any other large corporation. Standard database driven URL filters DO NOT WORK....PERIOD! I challenge you to call any district that is running their appliance to get their opinion of it in comparison to any of the other basic url filters out there. I did just that last week and they had absolutely nothing but high praises for the DN product. One even laughed at Websense which they had before switching simply for the lack of ability to block anonymouse proxies.