Table of Contents

Multiple Servers for Optimum Filtration

This guide with cover a deployment concept of using multiple server working in different roles to cover a variety of infrastructure and BYOD requirements to provide holistic filtration for a network. This requires a minimum of two ClearOS server but can be done with one so long as your default firewall/gateway has similar features to perform the role.

Transparent and Non-Transparent filtration

ClearOS provides a multitude of configuration option. Each with their advantages and disadvantage. To get the most out of both options, we will deploy both to work in conjunction with each other. This combines their strengths and removes their weaknesses.

Transparent filtration

Transparent proxies can filter non-SSL traffic but cannot filter SSL traffic without violating sound security principles. The only way to filter SSL without manipulating the workstation is block HTTPS. Moreover, they cannot negotiate with the web browser for authentication without employing a captive portal. They are limited to identifying the user by IP only as well. Because they can only identify by IP, they can only categorize traffic by the IP source.

However, they are straight-forward and fairly turnkey. They are great for Bring Your Own Device (BYOD) situations.

Non-Transparent filtration

Non-transparent filtration is great for identifying users, working with authentication models in the browser, filtering HTTPS and HTTP sites based on URLs. Reporting is more precise and because you can identify the user, you can classify them differently, even on the same machine.

However, they are lousy at ease of use. Non-transparent filtration required configuration of the browser. This can be mitigated by technologies like WPAD but there may exist issues with automatic detection.

Best of Both

Using both you can ensure filtration of all the traffic that leave your network.

Transparent Box

Your transparent box needs to pass port 80 traffic outbound and redirect it to your transparent proxy server. This happens automatically on ClearOS when you select transparent mode. Additionally, you will block all other traffic going out except for traffic that you approve. This will block traffic that is not filtered. The obvious exception to this is to allow the second box to navigate ports out.

BYOD device, devices not configured and services which don't support proxy settings will be able to surf the internet without settings. They won't be able to navigate https sites and you are limited to categorizing everyone the same way or by IP groups.

Non-Transparent Box

For the non-transparent box we can do the full treatment of user authentication, filtration policy groups, filtration of SSL traffic and others. To make this easy, we will set up WPAD on the network and a PAC file.

Step-by-step

This section will help you seamlessly deploy the solution in such a way to maximize your filtration and minimize the downtime and downside risks in deployment. The will ease your environment into a filtered mode and allow your users to adjust to the changes. Feel free to bypass any steps as appropriate to your environment.

What is nice about this method for migration is that it allows for an easy transition from a wide open network to a completely monitored and filtered one. If done properly with good testing and with patience, your users not even notice. search?q=clearos%2C%20clearos%20content%2C%20kb%2C%20bestpractices%2C%20maintainer_dloper%2C%20maintainerreview_x%2C%20keywordfix&btnI=lucky