For 10.30, the named daemon and DNS tools nslookup,
named-xfer, and
sig_named are
based on the public domain DNS release 4.9.3:
DNS (named, nslookup, named-xfer, sig_named) |
The following subsections describes the changes made for 10.30.
Support for Negative Caching |
 |
If an authoritative name server responds that the information
being queried does not exist for the specified domain name, the
local name server caches this negative response for a short period
of time (approximately 600 seconds). This can reduce the number
of successive DNS queries sent from the local name server and improves
response time.
Round-Robin |
|
When the name server supplies address information for a multi-homed
host, it cycles the returned order of those addresses. This provides
a mechanism for load sharing network traffic to each host interface.
If you do not need this feature, Hewlett-Packard offers the capability
of disabling this feature through a boot file options parameter
no-round-robin.
Round robin is enabled by default.
Additional "stub" Server Type Boot File Directive |
|
This feature is similar to a secondary server and is designed
to ensure that a primary for a zone can always have the correct
NS records for the children of that zone. This feature specifies
a child zone that your server should periodically get delegation
information for.
"Slave" Directive Depreciated |
|
The directive option options forward-only
now places a server in slave mode.
Non-recursive Servers |
|
The directive option options no-recursion
can be used to prevent your name server from performing recursive
resolution of domain names.
Query Logging |
|
The name server can log any query it receives to syslog
by using the boot file directive options query-log,
or through the use of the SIGWINCH signal. This is useful for system
administration. Be aware when using this option, syslog
could become large if enabled for a significant period of time or
if used on a busy name server.
Inverse Query Pseudosupport |
|
By default, BIND does not support inverse queries, which can
cause problems with older operating systems or NSLOOKUP tools. Using
the boot file directive options fake-iquery,
you can force the server to return a fake answer to any inverse
query rather than getting an "operation not implemented" error response.
Name Server Tuning |
|
Because some name server operations can be resource intensive,
it can sometimes be beneficial to tune the server internal quotas.
This can now be done with the following boot file directives:
- limit transfers-in
The number of simultaneous named-xfer processes
named is willing to start. (This can also be expressed by the depreciated
directive max-fetch.)
- limit transfers-per-ns
The maximum number of named-xfer processes named
is willing to initiate to any given name server simultaneously.
Security Type Changes |
|
Zone Transfer Restrictions
Using the boot file directive xfrnets,
it is now possible to control which neighbors can transfer zone
information from your server. For example:
xfrnets 16.0.0.0
all 16 network members |
xfrnets 16.1.0.2&255.255.255.255
only 16.1.0.2 |
Bogus Name Server Control
You can choose to refuse to listen to or ask questions of
any name servers known to give bad answers using the directive bogusns <address>
in the boot file.
Segmented Boot Files |
|
The include
directive in the named.boot
file now makes it possible to split the named.boot
file into multiple parts.
"options no-round-robin" |
|
For 10.30, there is an additional Hewlett-Packard implemented
boot file options directive options no-round-robin.
This option allows the default address cycling for multi-homed systems
to be disabled.
Resource Records |
|
Some newly supported Resource Record types are:
- ISDN
An ISDN telephone number
- AFSDB
Distributed Service data for a host
- RT
Route Through, similar use to an MX RR
- PX
Mapping rules between X.400 O/S style addresses
and RFC-822 domain style mail addresses
- X25
Carries PSDN address information
- NSAP
Carries NSAP address information
- LOC
Physical location information
- RP
Responsible Person email address for a host
- NULL
A null Resource Record (no format or data)
Command Line Options |
|
- -q
Trace all incoming queries. This option is depreciated
in favor of the boot file directive options query-log.
- -r
Turns off recursion in the server. This option is
depreciated in favor of the boot file directive options no-recursion.
Compatibility |
|
DNS for 10.30 is able to handle the existing database and
compatibility with the existing configuration files. However, round-robin
address cycling (described above) is enabled by default. If you
do not want this new feature, you can disable it by adding the following
entry to the named boot file (the default boot file is /etc/named.boot):
Printable version
