HOSTS file (redirected from Hostfile)

HOSTS file

A text file in a TCP/IP network that specifies the IP addresses of computer names and domain names (the host names). It is used to convert a request by name to a numeric IP address on the local network or the Internet. HOSTS files, which contain a host name and corresponding IP address on each line, were placed on clients and servers and manually updated.

HOSTS files have long since given way to the DNS name resolution system; however, they are still used to override DNS for testing purposes so that a Web browser or other application can be redirected to a specific IP address. In addition, by explicitly stating an IP address in a HOSTS file, a Web site can be retrieved more quickly, because the multiple transmit/receive steps a normal DNS query takes have been eliminated. See DNS.

HOSTS File Locations
In Windows, the HOSTS file is typically in the \windows\system32\etc folder. In the Mac, it is in /private/etc. The first line of a HOSTS file is 127.0.0.1 localhost. The "localhost" refers to the computer the HOSTS file is in, and the "127.0.0.1" is the loopback IP address of that same computer (see loopback address).

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(networking)

hosts file - A text file on a networked computer that was used to associate host names with IP addresses. A hosts file contains lines consisting of whitespace-separated fields giving an IP address followed by list of host names or aliases associated with that address. The name resolution library software can use this file to look up the IP address for a host name. The hosts file is "/etc/hosts" on Unix and "C:\Windows\System32\drivers\etc\hosts" or "lmhosts" on Microsoft Windows, Hosts files have now been almost entirely replaced by DNS, in which distributed servers provide the same information. A hosts file can still be used to override DNS for testing purposes or other special situations.