FSSO FortiGate Single Sign On

FSSO  KB ID 0001786

If you are applying polices with your FortiGate, e.g. Web Filtering or IPS, then the ability to track actual users rather than IP addresses is advantageous, it’s all very well blocking access to adult material or gambling sites, from the corporate network, but most companies want to know WHO is attempting to connect to what and when. 

To do that the firewall needs to learn what users are where, we can make all users actively authenticate to the firewall as they attempt to get on the web, but that does not make for a great user experience, it’s better to passively learn where your users are, and what machines they are using, then we can the use that in a policy. (let’s not get to far ahead for the moment).

Q. How do we learn where your users are, and what machines they are on?


To enable FSSO you need to understand the difference between two pieces of software, the FSSO Collector, and FSSO DC Agent. The DC Agent (as the name implies) run on each of your DCs, it captures login events and then does DNS lookups to see what machines people are using. The Collector takes the output from one or more DC Agents and collates it for the firewall, it does not have to run on a domain controller (but it can).

I only have one server! Well thats OK, both the collector and agent can be on the same box

FSSO Topology Single DC

However most networks will have multiple Domain Controllers, so your FSSO topology may look a little more like this.

FSSO Topology Single Collector

Or if you have an even larger network, you may want to build in a backup collector(s)

Multiple FSSO Agents and Collectors

Deploy FSSO

In my small test environment I’m going to put the collector and agent on a single DC. Your first challenge is actually getting the FSSO software. Log into your FortiCloud portal and proceed as if you want to download some FortiGate firmware.

Download FSSO Agent

Then in the version of FortiGate firmware that matches your firewall you will find an FSSO directory, (unless your’e in the dark ages your domain controllers will be x64 bit) so in my case I want FSSO_Setup5.0.0306_x64.exe (that will download the collector setup, that also includes the DC Agent software as well, which you can also download separately if you wish).

Install Collector

Accept the EULA, change the install directory if you don’t want it on the C: Drive > Enter some administrative credentials > Next.

Install FSSO Collector

My FortiGate has LDAPS Lookups so I’m going for Advanced > Next.

FortiNet FSSO Setup

Install > When complete, Im installing the DC Agent on the same server so MAKE SURELaunch DC Agent Install WizardIS ticked, and click finish.

Warning: Installing a DC Agent will result in the reboot of this DC, (you might want to do the next step out of hours).

FortiNet FSSO DC Agent

Install DC Agent

Accept the defaults > Next > Select the Domain > Next > Select any user(s) you want to be exempt > Next.

FSSO Collector IP and Port

Select DC Agent Mode > Next > It will prompt for a reboot, let it do so.

FSSO DC Agent Mode

Post reboot launch FortiGate Single Sign On Agent Configuration > And change the password to something memorable, (you will need to enter this onto the FortiGate in a minute).

FSSO DC Agent Setup

Register FSSO on FortiGate

Back on the Fortigate > Security Fabric EXTERNAL Connectors > FSSO Agent on Windows AD.

Add FSSO DC Agent To FortiGate

Give it a sensible name > Enter the IP address and the password you set above > Apply and Refresh > OK.

Configure FSSO Agent On FortiGate

You will know it’s working because it will give you a free up arrow (it can take a little while, be patient).

FSSO Status On FortiGate

Create FSSO Groups

Now you can add GROUPs based on FSSO learned groups, like so.

FSSO Active Directory Groups

Once you have the FSSO groups defined, you can use them in policies. Below I’ve added Domain Users to my default outbound policy.

WARNING: If you have any devices, or assets that need access out you will need to add a new rule to alow them out explicitly before this rule, or their internet access will suddenly stop.

FSSO Active Directory Groups in Fortigate policy 

Monitor FSSO Events

To make sure the system is working you can go to Events > User Events > Make sure your user logon activity is getting logged.

Log and Monitor FSSO Events

Related Articles, References, Credits, or External Links

FSSO Handbook

Author: PeteLong

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  1. Awesome post, finally the documentation I was looking for !!

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  2. Does this require any agent on the end user device at all

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