Address Groups can have a mixture of IPv4 and IPv6 Address Object types. As Access Rules are IPv4 and IPv6 specific, it is recommended to use separate Address Object Groups for IPv4 and IPv6 objects. This avoids having SonicOS unnecessarily processing IPv6 Address Objects when handling an IPv4 Access Rule. Similarly, avoids unnecessary IPv4 Address Object processing when handling traffic hitting an IPv6 Access Rule.
Generally, Address Groups can contain a mixture of Address Object types such as FQDN, MAC, Host, and others. However, there are configuration areas that can accept only a subset of those types or a specific type. A couple of examples are the ACL Enforcement/MAC Filter List which only accepts MAC type object, and the SSLVPN Client Routes, which does not support FQDN and MAC objects. SonicWall recommends avoiding the use of Address Groups that contain unsupported object types in configuration that supports only certain object types. In these scenarios it is best practice to use separate Address Groups containing only the supported object types.