CxBlock for Chromebook filtering
CxBlock is a remote filtering agent for Chromebook.
At the moment, CxBlock policy setup page is hidden. However, you still can
access it by using the URL 'http://your-server-ip/policy,cxblock.jsp'.
To use CxBlock, you have to check Enable Filter on 'Policy > Chromebook'.
Installation of CxBlock
CxBlock is basically a Chrome extension. You can install it from Chrome Web Store.
- Download CxBlock from Chrome Web Store

Connection to NxFilter
After you install it, you need to set up the following parameters on its setup page,
- Sever IP : The IP address of your NxFilter.
- Login Token : A login token associated to a user on NxFilter.
Once you set up these parameters you can test the connectivity using Test button. And then use
Save button to save and reload the new configuration.
- Login Token : A login token associated to a user on NxFilter.
Password protection
You can hide your CxBlock setup page from your users by having password login procedure.
Once you set up a password and enable it, the users will be blocked from accessing CxBlock setup page
and 'chrome://extension'.
You can use your Client Password on 'System > Admin' to access CxBlock setup page once its connection
to server is established.
If it's with NxCloud, you can use your operator password.
User identification
We use Login Token and Google Account to identify users. Suppose you create a user named 'student' on NxFilter
and install CxBlock to 100 Chromebook with the login token of 'student' user. Before they
login to Google they will appear on NxFilter log view as 'student'. But if one of them login
to Google using 'john1234@gmail.com' for example, then he will appear as 'student_john1234' on NxFilter
log view.
Central configuration file
When you install CxBlock en masse, you don't want to set up its connection parameters
one by one. To make things easier, we have a way for setting up these values centrally. We use Chrome's start page function.
You write a webpage containing some common config values and then make the webpage to be Chrome's start page on Google
Admin Console. Then everytime your users start their Chrome, they will set up their CxBlock with the config values.
When you write the webpage you add a meta tag like the following,
<meta name='cxblock' content='192.168.0.100:HW00IYKW:1'>
We have 3 parameters separated by colons. The first one is NxFilter's IP address and the second one is a login token
and the last one is about locking or unlocking Chrome's extension setup page.
On Google Admin Console,
- From the main dashboard, go to Device Management > Chrome > User Settings.
- Select the organizational unit to which you want the settings to apply.
- Find 'Pages to Load on Startup'.
- Enter the URL for the web page containing CxBlock configuration meta tag.
- Click the 'Save Changes' button.
When you have multiple start pages, it should be the first one.