All domain names used in a single update request must belong to the same DNS zone. A blank line causes the accumulated records to be formated into a single update request and transmitted to the zone's authoritative name servers. Additional records may follow, which are formed into additional, completely independent update requests. For the last request to be transmitted, a blank line must end the input.
Records take one of two general forms.
A update request consists of zero or more prerequisites and one or more updates. Each update request is processed atomically - all prerequisites must be satisfied, then all updates will be performed. Requires that no RR of any type exists with name Requires that at least one RR named must exist. Requires that no RR exists of the specified and Requires that a RR exists of the specified and If is specified, it must match exactly. Adds a new RR with specified and The following example illustrates the interactive use of to change an IP address by deleting any existing A records for a domain name and then inserting a new one.