HP-UX IP Address and Client Management Administrator's Guide HP-UX 11i v2, HP-UX 11i v3

Dual-Stack Server Option
BIND provides transition support for IPv4 and IPv6 to solve problems caused by the lack of
support for either IPv4 or IPv6 address on a host system. It also provides the
dual-stack-servers option to enable the transition support for IPv4 and IPv6 addresses.
This option specifies host names or addresses of systems that have access to both IPv4 and IPv6
transports. If the host name is specified, a name server resolves a host name using the transport
supported by the name server. The dual-stack-servers option does not have any affect in
a dual-stacked system, if access to the IPv4 or IPv6 transport is disabled using the named -4 or
named -6 command.
The syntax for the dual-stack-servers option in the options statement in the /etc/
named.conf file is as follows:
[ dual-stack-servers [port ip_port] { ( domain_name [port ip_port] |
ip_addr [port ip_port] ) ; ... }; ]
Additional Options
Following are some additional options in the options statement:
• tkey-domain
This option specifies the domain name that is appended to the shared keys generated by
TKEY. When a client requests a TKEY exchange, it may or may not specify the desired name
for the key. If the client specifies the desired name for the key, the shared key name is a
combination of the client-specified part and the tkey-domain; otherwise, the shared key
name is a combination of the random hexadecimal digits and the tkey-domain. In most
cases, the domain name must be the server’s domain name.
• tkey-dhkey
This option specifies the Diffie-Hellman key used by the server to generate shared keys
with clients using the Diffie-Hellman mode of TKEY. The server must be able to load
the public and private keys from files in the working directory. In most cases, the key name
must be the server’s host name.
• port
This option specifies the port number.
The sortlist Statement
The response to a DNS query consists of multiple resource records forming a resource record
set. The name server replies to a query with a resource record set in an indeterminate order. The
client resolver code must rearrange the resource records appropriately on the local network
depending upon a particular preference.
You can use the sortlist statement to specify the preference of an IP address over other IP
addresses. The sortlist statement contains the address_match_list option, which is a list
of addresses that specify the preference. Each top-level statement in the sortlist statement
must be an explicit addresses_match_list with one or two elements. The first element, which
can be an IP address, IP prefix, acl name, or a nested address_match_list, is checked against
the source address of the query until a match is found.
When the source address of the query is matched, if the top-level statement contains only one
element, the actual element that matches the source address is used to select the address in the
response to move to the beginning of the response. Each top-level statement element is assigned
a distance, and the address in the response with the minimum distance is moved to the beginning
of the response. For more information on the sortlist statement, type man 1M named.conf
at the HP-UX prompt.
BIND Name Service Overview 39