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Fortigate VDOMs

Fortigate VDOMs


What are Fortigate VDOMs(Virtual Domains)?

Well Fortigate VDOMs are like ASAs contexts, you are able to separate the firewall so it looks like you have 2, with different management and user groups. With ASA you lose some features when you enabled contexts, but in the Fortinets’ Firewall you do not lose any features.(Isn’t that just great?!)

VDOMs features:

1. Have separate routing and firewall services

2. Each physical interface belongs to only one Virtual Domains

3. By Default for the VDOMs to communicate you need an external source(Internet) to allow the communications

4. By Default 10 VDOMs are supported (in NAT or Transparent Modes)

5. The Configuration file of the Fortigate, holds all VDOM configuration. EX: AntiVirus, IPS and System Time


I. VDOM Configuration Features:


Fortigate Tutorial – Web Filtering

Fortigate Tutorial – Web Filtering


Fortigate processes Web Filtering options in the following order:

1. URL Filtering

2. Fortiguard Web Filtering

3. Content Exempt

4. Content Block

5. Script Filter

6. Antivirus


Let’s talk a little about all of them:

1. URL Filtering – you define what URLs the Fortigate can block

2. Fortiguard Web Filtering – based on the categories you choose, the Fortigate will block the pages

3. Web Content block

This option blocks specific words or patterns. You can use Perl regular expressions and the based on scores you can block those

4. Web Content Exemption – allows the administrator to override the web content block feature.

Fortigate Tutorial – Spam Filtering

Fortigate Tutorial – Spam Filtering


Fortiguard uses the industry standard definition of spam as Unsolicite Bulk Email.

Here are the Spam Filtering Methods implemented by Fortinet to its appliances:

1. IP Address Check

2. URL Check

3. Email Checksum Check

4. Spam Submission

5. Block/White List

6. HELO DNS Lookup

7. Return E-mail DNS check

8. Banned Words

9. MIME check

10. DNS Blackhole List (DNSBL) and Open Relay Database List (ORDBL)


II. Fortiguar AntiSpam

Global Filters

1. FortiIP Sender IP Reputation Database (based on the reputation of the IP)


Fortigate Tips and Tricks

Fortigate Tips and Tricks

This article presents some useful commands/tricks that you can do to your Fortigate.


Debug Addresses:
Many times it happens that we have a lot of firewall policies for one address defined in our address Pool.
Let’s take an example:
We have “WWW_Server” defined with the IP of To see what policies are using this Address we can use the following:

#diag sys checkused firewall.address:name ‘WWW_Server’
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Fortigate | Fortinet Antivirus



It this post i will talk about the AntiVirus feature of Fortigate. Since the firewall from Fortinet has a lot of features it is normal that AntiVirus is one of them.

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The processing of the Antivirus application goes as following:

1. File Filter -first it checks if any files match a file filter defined by you. Ex: block any “.exe” files

2. Virus Scan – it then scans the file for known viruses