HP-UX Reference (11i v2 04/09) - 4 File Formats (vol 8)

n
named.conf(4) named.conf(4)
tcp-clients
The maximum number of simultaneous client TCP connections that the server will accept.
Default is 100.
max-cache-size
The maximum amount of memory to use for the server’s cache, in bytes. When the amount of
data in the cache reaches this limit, the server will cause records to expire prematurely so that
the limit is not exceeded. In a server with multiple views, the limit applies separately to the
cache of each view. Default is unlimited
, meaning that records are purged from the cache
only when their TTLs expire.
Periodic Task Intervals
cleaning-interval
The server will remove expired resource records from the cache every
cleaning-interval
minutes. The default is 60 minutes. If set to 0, no periodic cleaning will occur.
heartbeat-interval
The server will perform zone maintenance tasks for all zones marked as dialup whenever this
interval expires. Default is 60 minutes. Reasonable values are up to 1 day (1440 minutes). If
set to 0, no zone maintenance for these zones will occur.
interface-interval
The server will scan the network interface list every interface-interval
minutes.
Default is 60 minutes. If set to 0, interface scanning will only occur when the configuration file
is loaded. After the scan, listeners will be started on any new interfaces (provided they are
allowed by the
listen-on configuration). Listeners on interfaces that have gone away will
be cleaned up.
The sortlist Statement
The response to a DNS query may consist of multiple resource records (RRs) forming a resource records
set (RRset). The name server will normally return the RRs within the RRset in an indeterminate order.
The client resolver code should rearrange the RRs as appropriate, i.e., using any addresses on the local
net in preference to other addresses. However, not all resolvers can do this or are correctly configured.
When a client is using a local server the sorting can be performed in the server, based on the client’s
address. This only requires configuring the nameservers, not all the clients. The sortlist statement (refer
to the sortlist section below) takes an
address_match_list
and interprets it. Each top level state-
ment in the sortlist must itself be an explicit
address_match_list
with one or two elements. The
first element (which may be an IP address, an IP prefix, an ACL name or a nested
address_match_list
) of each top level list is checked against the source address of the query until a
match is found.
Once the source address of the query has been matched, if the top level statement contains only one ele-
ment, the actual primitive element that matched the source address is used to select the address in the
response to move to the beginning of the response. If the statement is a list of two elements, then the
second element is interpreted in a special way. Each top level element is assigned a distance and the
address in the response with the minimum distance is moved to the beginning of the response. In the fol-
lowing example, any queries received from any of the addresses of the host itself will get responses
preferring addresses on any of the locally connected networks. Next will be addresses on the
192.168.1/24 network, and after that either the 192.168.2/24 or 192.168.3/24 network with no preference
shown between these two networks. Queries received from a host on the 192.168.1/24 network will prefer
other addresses on that network to the 192.168.2/24 and 192.168.3/24 networks. Queries received from a
host on the 192.168.4/24 or the 192.168.5/24 network will only prefer other addresses on their directly
connected networks.
sortlist {
{ localhost;
// IF the local host
{ localnets;
// THEN first fit on the
192.168.1/24;
// following nets
{ 192.168.2/24; 192.168.3/24; }; }; };
{ 192.168.1/24;
// IF on class C 192.168.1
{ 192.168.1/24;
Section 4−−190 Hewlett-Packard Company − 15 − HP-UX 11i Version 2: September 2004