Chapter 5 – Best Practices

Chapter 5 – Best Practices


This FortiGate Best Practices document is a collection of guidelines to ensure the most secure and reliable operation of FortiGate units in a customer environment. It is updated periodically as new issues are identified.


General Considerations

1. For security purposes, NAT mode is preferred because all of the internal or DMZ networks can have secure private addresses. NAT mode policies use network address translation to hide the addresses in a more secure zone from users in a less secure zone.

2. Use virtual domains (VDOMs) to group related interfaces or VLAN subinterfaces. Using VDOMs will partition networks and create added security by limiting the scope of threats.

3. Use Transparent mode when a network is complex and does not allow for changes in the IP addressing scheme.


Customer service and technical support

For antivirus and attack definition updates, firmware updates, updated product documentation, technical support information, and other resources, please visit the Fortinet Technical Support web site at

You can also register Fortinet products and service contracts from and change your registration information at any time.

For information about our priority support hotline (live support), see When requesting technical support, please provide the following information:

  • Your name, and your company’s name and location
  • Your email address and/or telephone number
  • Your support contract number (if applicable)
  • The product name and model number
  • The product serial number (if applicable)
  • The software or firmware version number
  • A detailed description of the problem


Fortinet Knowledge Base

The most recent Fortinet technical documentation is available from the Fortinet Knowledge Base. The knowledge base contains short how-to articles, FAQs, technical notes, product and feature guides, and much more. Visit the Fortinet Knowledge Base at


Comments on Fortinet technical documentation

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System and performance

By implementing the following best practices for system and performance, you will ensure maximum efficiency of your FortiGate device. Be sure to read everything carefully, particularly the section that concerns shutting down the FortiGate system, in order to avoid potential hardware issues.



  • Disable any management features you do not need. If you don’t need SSH or SNMP, disable them. SSH also provides another possibility for would-be hackers to infiltrate your FortiGate unit.
  • Put the most used firewall rules to the top of the interface list.
  • Log only necessary traffic. The writing of logs, especially if to an internal hard disk, slows down performance.
  • Enable only the required application inspections.
  • Keep alert systems to a minimum. If you send logs to a syslog server, you may not need SNMP or email alerts, making for redundant processing.
  • Establish scheduled FortiGuard updates at a reasonable rate. Daily updates occurring every 4-5 hours are sufficient for most situations. In more heavy-traffic situations, schedule updates for the evening when more bandwidth can be available.
  • Keep security profiles to a minimum. If you do not need a profile on a firewall rule, do not include it.
  • Keep VDOMs to a minimum. On low-end FortiGate units, avoid using them if possible.
  • Avoid traffic shaping if you need maximum performance. Traffic shaping, by definition, slows down traffic.

Having trouble configuring your Fortinet hardware or have some questions you need answered? Check Out The Fortinet Guru Youtube Channel! Want someone else to deal with it for you? Get some consulting from Fortinet GURU!

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