Hosts (file)

hosts filehosts/etc/hostshosts fileshostHOSTS.TXT/etc/hosts filehost filehost fileshost table
The computer file hosts is an operating system file that maps hostnames to IP addresses.wikipedia
110 Related Articles

Name Service Switch

nsswitch.confNSS/etc/nsswitch.conf
In modern operating systems, the hosts file remains an alternative name resolution mechanism, configurable often as part of facilities such as the Name Service Switch as either the primary method or as a fallback method. In some operating systems, the contents of the hosts file is used preferentially to other name resolution methods, such as the Domain Name System (DNS), but many systems implement name service switches, e.g., nsswitch.conf for Linux and Unix, to provide customization.
These sources include local operating system files (such as /etc/passwd, /etc/group, and /etc/hosts), the Domain Name System (DNS), the Network Information Service (NIS), and LDAP.

Hostname

host namehosthostnames
The computer file hosts is an operating system file that maps hostnames to IP addresses.
This kind of hostname is translated into an IP address via the local hosts file, or the Domain Name System (DNS) resolver.

Domain Name System

DNSresource recordDNS record
The Domain Name System, first described in 1983 and implemented in 1984, automated the publication process and provided instantaneous and dynamic hostname resolution in the rapidly growing network. In some operating systems, the contents of the hosts file is used preferentially to other name resolution methods, such as the Domain Name System (DNS), but many systems implement name service switches, e.g., nsswitch.conf for Linux and Unix, to provide customization.
The Stanford Research Institute (now SRI International) maintained a text file named HOSTS.TXT that mapped host names to the numerical addresses of computers on the ARPANET.

Spyware

anti-spywareantispywareSpyware removal software
;Internet resource blocking: Entries in the hosts file may be used to block online advertising, or the domains of known malicious resources and servers that contain spyware, adware, and other malware.
Some users install a large hosts file which prevents the user's computer from connecting to known spyware-related web addresses.

Localhost

loopback addresslocal loopbacklocal machine
This may be achieved by adding entries for those sites to redirect requests to another address that does not exist or to a harmless destination such as the local machine.
The resolution of the name localhost to one or more IP addresses is normally configured by the following lines in the operating system's hosts file:

Mydoom

DoomjuiceMydoom wormMydoom.B
The widespread computer worm Mydoom.B blocked users from visiting sites about computer security and antivirus software and also affected access from the compromised computer to the Microsoft Windows Update website.
A second version, Mydoom.B, as well as carrying the original payloads, also targets the Microsoft website and blocks access to Microsoft sites and popular online antivirus sites by modifying the hosts file, thus blocking virus removal tools or updates to antivirus software.

Computer file

filefilescomputer files
The computer file hosts is an operating system file that maps hostnames to IP addresses.

IP address

IP addressesIPdynamic IP address
The computer file hosts is an operating system file that maps hostnames to IP addresses. It is a common part of an operating system's Internet Protocol (IP) implementation, and serves the function of translating human-friendly hostnames into numeric protocol addresses, called IP addresses, that identify and locate a host in an IP network.

Plain text

textplain-texttexts
It is a plain text file.

ARPANET

ARPA networkDarpanetAdvanced Research Projects Agency Network
Originally a file named HOSTS.TXT was manually maintained and made available via file sharing by Stanford Research Institute for the ARPANET membership, containing the hostnames and address of hosts as contributed for inclusion by member organizations.

Internet Protocol

IPIP protocolInternet Protocol (IP)
It is a common part of an operating system's Internet Protocol (IP) implementation, and serves the function of translating human-friendly hostnames into numeric protocol addresses, called IP addresses, that identify and locate a host in an IP network.

Directory service

directorydirectory servername service
In some operating systems, the contents of the hosts file is used preferentially to other name resolution methods, such as the Domain Name System (DNS), but many systems implement name service switches, e.g., nsswitch.conf for Linux and Unix, to provide customization.

Linux

GNU/LinuxLinux on the desktopLin
In some operating systems, the contents of the hosts file is used preferentially to other name resolution methods, such as the Domain Name System (DNS), but many systems implement name service switches, e.g., nsswitch.conf for Linux and Unix, to provide customization.

Unix

UNIX operating systemAT&T UnixUnix-like
In some operating systems, the contents of the hosts file is used preferentially to other name resolution methods, such as the Domain Name System (DNS), but many systems implement name service switches, e.g., nsswitch.conf for Linux and Unix, to provide customization.

IPv4

Internet Protocol version 4IPv4 addressIP header
The example illustrates that an IP address may have multiple host names (localhost and loopback), and that a host name may be mapped to both IPv4 and IPv6 IP addresses, as shown on the first and second lines respectively.

IPv6

Internet Protocol version 6dual-stackstateless address autoconfiguration
The example illustrates that an IP address may have multiple host names (localhost and loopback), and that a host name may be mapped to both IPv4 and IPv6 IP addresses, as shown on the first and second lines respectively.

File system

filesystemfile systemsfilesystems
The location of the hosts file in the file system hierarchy varies by operating system.