Dents is DNS name server designed to be a drop in replacement for ISC BIND. Dents is available from www.dents.org and is released under the
GNU General Public Licence.
The DNS name space is divided into domains. The zero level
domain (.) covers all DNS names. Top level domains, such
as .org and .au are subdomains of the zero
level domain and are also domains in their own right. Any domain may have
a subdomain, so dents.org is a subdomain of the .org
top level domain and slarken.org.au is a subdomain or
.org.au, which is in turn a subdomain of the top level domain,
.au.
In name server terms, a zone is complete information about
some part of the DNS name space. Usually a domain, less information about
subdomains that is controlled by another name server. For example,
the name server for slarken.org.au may be authorative for
the hosts www.slarken.org.au and ftp.slarken.org.au,
but a subdomain hype.slarken.org.au may be controlled
by another name server. In this case the zone for slarken.org.au
would contain information about www.slarken.org.au and
ftp.slarken.org.au as well has information about the name
server for the hype.slarken.org.au subdomain.
Dents allows zones to be mounted in the name space much in the same way
that UNIX allows partitions to be mounted in a directory structure.
Just as different mounted partitions in a directory structure may
have different file systems controlled by different portions
of code in the kernel, Dents allows different zones types,
controlled by driver modules.
Access to a root name server is analogous to the / directory
in a UNIX directory structure. Dents allows this zone to be mounted and
resolved using the driver module mod_recursive. BIND for one
uses RFC 1035 style zone
files. This is supported in Dents by mounting a zone using
the mod_stddb driver module.
One advantage of being able to use different driver modules is that
arbitrary modules may be defined. Driver modules that access zone
information stored in a relational data base or produce standard mappings
from an IP address to a hostname for dialup pools are two
example applications.
Super Sparrow is able to return results obtained from BGP speaking route servers using a Dents driver
module, mod_supersparrow.
A work around for this bug is to manually copy zone files to
slave servers and configure them as masters. This is less
than perfect but is a workable solution until the Dents
code is fixed.
Please see references.
Copyright © 2000 HormsCaveats
The Dents shipped with Super Sparrow is a development
version of Dents 0.4.0. There are two known problems with this
release:
If you compile dents with pthreads enabled then it will not
work. The RPM and SRPM of dents supplied with Super Sparrow are
configured to use Dents without pthreads. If you compile Dents directly
from source you should use configure to disable pthreads support.
./configure --without-pthreads [--prefix=/usr]
The mod_stddb driver module that supports RFC 1035 style zone files
has an option to handle slave zones. As part of this the zone must
be transfered from the master by Dents. This does not
work. You should not use dents configured with slave zones
or these zones will not be resolvable by the dents server.
References
Last Updated: Sun Nov 26 07:46:45 2000