As a general rule, the latest release in a given train (6.4.x, 7.0.x, etc) is the 'most stable' in that it has found and corrected issues in the previous releases. Ultimately, it is a decision customers need to determine based on what technologies they are running while considering interoperability with other Fortinet technologies as well as any known issues documented in a particular release.
To build on the excellent responses you've received already, Fortinet has also recently started labeling their firmware releases as either "Feature" releases (marked "F") or "Maturity" releases (marked "M"). As major releases mature from the first few point releases, i.e. 7.0.1, .2, .3, there are bugs being fixed but at the same time new features as well. As the release becomes more mature, the later releases will be fixing bugs primarily.
Ideally, if you are concerned about stability, stick with the "M" releases (which is 6.4.10 today).
If there are features in 7.0 that you absolutely need, then ideally you have an environment within which you can test it out before rolling to production.
Thank you so much for your quick response. We have checked the detail of firmware from support portal. The F mark only with 7.0.6 and 7.2.1 and M mark with 6.4.10. Due to stability i think we should go on 6.4.10 that already you have suggested to me.
FortiOS 7.0 and onward versions are relatively new, and as with any new software release, there may be some stability and compatibility issues that need to be addressed. However, the general consensus among Fortinet users and experts is that FortiOS 7.0 is stable and performs well.
Here are some factors to consider when deciding whether to upgrade to FortiOS 7.0 or later versions:
1. Compatibility: Make sure that any third-party software or hardware you are using with your Fortinet devices is compatible with FortiOS 7.0 or later versions. You should also verify that your Fortinet devices are capable of running FortiOS 7.0 or later versions.
2. Features: Consider the new features and improvements that are included in FortiOS 7.0 or later versions. Are there any features that are particularly useful for your organization? Are there any features that are not relevant or useful to you?
3. Security: Consider the security improvements and enhancements that are included in FortiOS 7.0 or later versions. Do these improvements address any security concerns or vulnerabilities that are important to your organization?
4. Support: Make sure that you have access to support resources, such as documentation, forums, and technical support, in case you encounter any issues during or after the upgrade process.
Overall, if you have thoroughly evaluated the compatibility, features, security, and support considerations, and have determined that upgrading to FortiOS 7.0 or later versions is appropriate for your organization, it is likely that you will experience a stable and efficient system. However, it is always recommended to test the upgrade in a lab environment before rolling it out to production to minimize any potential disruptions.
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