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Page modified: Friday, June 23, 2006 20:29:01

BIND (Berkeley Internet Name Domain) is an open SOURCE software package, with which on computers with standard operating systems (e.g. UNIX, NetBSD, FreeBSD, OpenBSD, Linux, Mac OS X, Windows NT, z/OS) a Domain Name System server can be implemented. BIND can be referred free of charge, for that SOURCE code is published. Due to his far spreading and the timenear conversion of the current DNS RFCs applies BIND for years as DNS reference software.

History

Before there was DNS, the dissolution of names in IP addresses over lists (/etc/hosts.txt, see /etc/hosts on today's Unix systems) was made, which had to be present on each computer in the Internet. Changes were accomplished manually first on a master server and distributed then by file down load to the individual computers. With rising number of IP participants this procedure became increasingly more unmanageable.

1983 were specified by Paul Mockapetris the Domain Name System (DNS). In the same year the first DNS software - JEEVES - on a DEC computer was implemented. The first three Internet root server went a little later into enterprise.

Beginning of the 80's were worked on the University of Berkeley on the advancement of UNIX. Some students began to write for UNIX a DNS software which it BIND (Berkeley Internet Name Domain) baptized. BIND one developed further and the version 4 became constantly the world-wide standard. After the Berkeley university had stopped the advancement of the software, the responsibility was taken for short time by the company DEC and afterwards by Vixie Enterprises. Paul Vixie was at this time floating Kraft behind the project.

Starting from the version 4.9.3 went BIND into the responsibility of the producer-independent ISC (Internet software Consortium - starting from 2004: Internet of system Consortium) over. The version 8 was finished 1997. 1999 assigned ISC the company Nominum Inc. to develop the version 9. BIND 9 is today (at the beginning of of 2004) standard. The version 8 is still widespread, version 4 is considered as become outdated.

Configuration

With BIND concerns it in the long run a normal computer program: It is started, it does something and it is terminated (or is terminated). The behavior of the program is determined by configuration files which can be provided manually, which are read in with program start. It exists a global file - usually with the name named.conf - and per zone a zone file, whose name is usually formed from the zone name and the Extension .db (there is permissible also arbitrary other names).

Example: Accepted, the name server should be masters for the zones example.com and test.example.com. Then the following files must be present: named.conf, example.com .db and test.example.com .db.

The master zone files contain at least a SOA resource record, one or more LV resource record and any number of further RRs like for example A resource record or PTR resource record. The master zone files define thereby contents of a zone. The Slave Zonendateien does not have to be produced in every case manually. With application of the Notify procedure (see zone transfer) they are produced automatically.

named.conf

The information is accommodated in different ranges. The most important are:

Global range
Server list
Zone list

Within the global range access authorizations, Krypto keys and options are defined (see bind option). In the server list information about partner servers is contained (e.g. whether a server supports incremental zone transfer). In the zone list an entry is contained for each zone, which the names of the zone, which contains names zone files, the type of zone (master or Slave), access authorizations as well as option.

Example:

         option {allow transfer {local host; 172.27.157.16; }; host statistics YES; notify YES; };

         server 172.27.157.16 {bogus NO; support ixfr yes; };

         zone "example.com" {type master; file "example.com.db"; notify YES; };

Function mode

After reading the configuration files in takes BIND all packages against, which arrive at the UDP haven 53 and TCP haven 53 of the interfaces or IPA (n), configured. With these packages it can concern DNS inquiries, dynamic updates or zone transfers. If an DNS inquiry is present, then tried BIND it on the basis the entries in the zone files to dissolve. With unknown zones first the Cache is examined and tried a recursive dissolution if this is activated. With DNS updates the zone file concerned is updated, if the releasing is in addition justified and verified.

Installation and enterprise

With UNIX or Linux systems is BIND often contained in the scope of supply. New versions can from the Internet either as binary package (for Windows) or as SOURCE code to be downloaded. Middle UNIX knowledge is sufficient for the installation and enterprise of a binding server. With Windows-NT/2000 a compressed binary file is downloaded. The installation is simple.

When changes in zone files may not be forgotten to increment the serial number and this change BIND admits to make, is it by a complete restart of the server, a SIGHUP (UNIX) or over the management Tools ndc (BIND 8) and/or rndc (BIND 9). Are available a set of LOGGING and statistics functions, with which the work of the software can be examined.