URL format

Specify the RMI registry name or address. The default name is localhost.
Specify the RMI registry port number. The default port is 53.
The domain is the DNS domain name of the context, and is not necessarily related to the domain of the server; it defaults to ".", the root domain.
The IP host name of the object to lookup
DNS resource record class and type names are mapped onto JNDI attribute identifiers.

If a record is in the internet class, the corresponding attribute ID is simply the record's type name.

If the type is an unsupported one, its integer value is used instead. If the record is not in the internet class, the class name or integer class value is pre-pended to the attribute ID and separated by a space.

For example, the attribute identifier "AAAA" represents an IPv6 address record, and the attribute identifier "HS 97" represents a resource record of type 97 in the Hesiod class.

Superclass attribute identifiers are also defined. These can be useful when querying records using the DirContext.getAttributes() method. If an attribute name has "*" in place of a type name or class name, it represents records of any type or class. For example, the attribute identifier "IN *" might be passed to the getAttributes() method to find all internet class records.

The default attribute identifier "* *" represents records of any class or type.

Attribute identifiers are case-insensitive.