In some

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

distributions, and other

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

-like

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

s, the resolvconf program maintains the system information about the currently available

name server A name server refers to the server component of the Domain Name System (DNS), one of the two principal namespaces of the Internet. The most important function of DNS servers is the translation (resolution) of human-memorable domain names (example. ...

s and manages the contents of the

configuration file In computing, configuration files (commonly known simply as config files) are computer file, files used to configure the Parameter (computer programming), parameters and Initialization (programming), initial settings for some computer programs. T ...

resolv.conf resolv.conf is the name of a computer file used in various operating systems to configure the system's Domain Name System (DNS) resolver. The file is a plain-text file usually created by the network administrator or by applications that manage ...

'', which determines

Domain Name System The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ...

(DNS) resolver parameters. Before a computer can connect to an external network resource by name, it must convert that alpha-numeric name (e.g., ''wikipedia.org'') into its corresponding

network address A network address is an identifier for a node or host on a telecommunications network. Network addresses are designed to be unique identifiers across the network, although some networks allow for local, private addresses, or locally administere ...

called an

IP address An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...

(e.g., ''66.230.200.10''). The computer performs this conversion by contacting one of a number of special computers called name servers, which have tables of resource names and corresponding IP addresses. The information about the servers is kept in the configuration file ''resolv.conf''. However, when multiple programs need to dynamically modify the ''resolv.conf'' file, they can interfere with each other and store incorrect information in the file. The ''resolvconf'' program addresses this problem. It acts as an intermediary between programs that supply name server information (e.g.,

DHCP The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) networks for automatically assigning IP addresses and other communication parameters to devices connected to the network using a cli ...

clients) and programs that use name server information (e.g., resolvers). When ''resolvconf'' is properly installed, the ''resolv.conf'' file is replaced by a

symbolic link In computing, a symbolic link (also symlink or soft link) is a file whose purpose is to point to a file or directory (called the "target") by specifying a path thereto. Symbolic links are supported by POSIX and by most Unix-like operating system ...

to and the resolver instead uses the dynamically generated linked file. In a system without resolvconf, the file is normally maintained manually or by a collection of scripts. The scripts may cause problems, because there is no program to control access to the file. Resolvconf controls access to the file, allowing many programs to use it at the same time. resolvconf cannot easily be disabled on some systems. On FreeBSD it can be disabled by placing in . In securely administered environments the resolvconf program (or

daemon Daimon or Daemon (Ancient Greek: , "god", "godlike", "power", "fate") originally referred to a lesser deity or guiding spirit such as the daimons of ancient Greek religion and mythology and of later Hellenistic religion and philosophy. The word ...

, depending on the implementation) causes uneasiness since it interferes with the containment of security vulnerabilities, making changes to it without authorization. (Centralized change management, or centralized compliance, requires that system changes cannot be made from the sidelines.)

References

External links

resolvconf
– Original implementation.
openresolv
– Compatible implementation.
192-168-i-i.com
Domain Name System Configuration files {{compu-domain-stub