Troubleshooting Tip: Error 'Invalid name: end-ip is out of range from start-ip, must be in the same Class C subnet for ipv4' in FortiMail IP Group

Sometimes, to optimize the use of policies in FortiMail, it is necessary to combine IP version 4 and version 6 addresses within the same IP Group. In some cases, the following error may be displayed:

This error is displayed when the default IP version 6 address::/0 is combined with any IP version 4 address, regardless of class.

This is not a functional error, it is a limitation defined by design since if the IP address pool is too large, pool verification can potentially consume a lot of resources, jeopardizing system performance.

To correct this, create multiple IP Groups containing the necessary subnets as needed, such as:

Or use the default IP version 6 address,::/0, directly in the policy and not within an IP Group: