The Reconfigure mechanism requires that the server sends Authentication Option (11) to the clients to communicate the authentication key during the Solicit/Reply, Request/Reply and Information-request/Reply transactions. It also uses this option in the Reconfigure messages. The option comprises a record of fields and can't be represented by any of the existing options. The limitation of the OptionCustom class is that the Auth option has the 64-bit field for Replay Detection and OptionCustom does not support 64-bit fields. We could extend the OptionCustom but in fact it is better (and cleaner) to have a dedicated class to represent Auth Option as it has very specific usage and a few convenience functions could be added to this new class to make it easy to manipulate this option. The OptionCustom is very generic.