NxFilter
Starting Nov 11th, 2020 we will be switching to a new web-filtering system (shutting down SafeDNS) powered by NxFilter. This will be run on a server we control, which is different from previous services where we were more or less at their mercy. SafeDNS has been disconnecting the internet and other issues that have plagued us for months. The new system means there are some changes to be aware of.
The web filter will show a similar block screen as with the previous web filter with a button to request a whitelist.
This works without issue on HTTP sites but can cause issues on HTTPS sites (this is due to how SSL security works). We installed an extension (CxForward) on Chrome and Edge browsers which fix the block screen, but for Firefox you will see an SSL security error instead.
If you use Firefox primarily and do run into that security warning, try opening the same site in Chrome or Edge to see if it is blocked or truly an error with the website.
Logging In
There are some staff which need access to normally blocked categories. For those individuals, they will log in at http://login.coursevector.com/block,login.jsp using their first name and last initial as the username. Then use their computer password as their password. For example:
Username: GabeM
Password: <my computer password>
Once logged, please restart your browser.
SafeDNS
This will expire on Nov 14th, 2020 when the contract expires. We had much trouble with this system and it’s instability which is why it is being abandoned. This was replaced with NxFilter.
How a web-filter works
Web filtering is not an exact science. As a matter of fact, filtering has to be “taught” what to filter. We start out buying a package, that is basically a generic filtering system. Then we “teach” it to adapt to our work parameters.
On the next several pages, you can see the “categories” that we purchased and whether they are allowed or blocked. Any “group” with a check mark will allow all web sites within that group.
In most cases, when you request to have a URL white listed, IT will simply white list that specific web site. However, in some cases, you should open a ticket requesting that we review an entire group. For instance, currently, you will see that Abused Drugs are blocked. The logic, on the part of IT, was Viagra, etc. However, the programs department researches issues pertaining to drug and alcohol testing. Therefore, in this case, the entire group was set to allow.
There are two more specific examples that should be noted:
At the bottom of the list, you will see “Unavailable” is blocked. That means anything not contained in our allowed list is blocked. We cannot allow this group as hackers open thousands of web sites daily and we need to protect PSAB from these potential threats. Please understand that we will need to white list URLs in this category, so simply click the link when the blocked message appears which will submit the URL for white listing.
If you Google something, and the link returned has a yellow Ad box beside it, you will not be able to visit that site. Links with the word Ad at the top of a Google search are actually paid links that Google posts on the search page. These links to do not actually go to the indicated website, but rather are “redirected” through servers that track your name, address, location, etc. and then, you are forwarded to the actual website. Virus scanners and filters cannot deal with redirection, so they simply block the site. In 99.9% of the cases, you can scroll down the Google search results and find the same link, but without the Ad box. Those will normally work.
We hope this explanation will help staff understand the use of web filtering. As time goes on, the filter will require less and less adjustments and will settle in to “our” work patterns.
