The specified method must not be especially onerous or unreasonable. The specified method must not allow any SLD to have an unreasonable visible advantage or disadvantage with respect to the updating of the database. The specified method must be reasonably secure. The DA will be required to follow these policies to an extent that will be considered reasonable should any decision be challenged in the future. A standard implementation of bind, running on a well connected machine with a minimum of two well connected independant secondary hosts should meet the connectivity and interrogation requirements.
Disaster recovery is possible via the secondary hosts in the majority of cases.
Daily backups of the authority record, and a reasonably complete record of transactions will be considered a reasonable meeting of this duty of care. The policy will need to be tight enough to allow only very little need for interpretation. Distributed updating of the name database will be an interesting technical issue. It would be reasonable for a DA to require that such a method be used. A high level of cooperation will be required between the DA in order for such a process to be implemented.