/CACHE=([NO]DOMAIN:do,[NO]FILE:file)

    Optional. Default: None.

    Specifies the cache server for the specified domain. Do not use
    with /FORWARDERS. Use with /PRIMARY and /SECONDARY.

    The cache tells the primary or secondary server how to use hints
    to find the file. These hints let a server find a root name
    server. With this ability, the server can answer requests even
    if it does not have the information. You can use the following
    options:

    o  DOMAIN keys to a particular record within a type.

       NODOMAIN deletes the entry.

    o  FILE specifies the name of the hints file.

    If you use /CACHE with no options:

    o  DOMAIN defaults to "." ("root").

    o  FILE defaults to NAMED.CA.