Pasted below this question is a sample of a /etc/hosts file from a Linux (CentOS) and a Windows machine. The Linux file has two tabbed entries after the IP address (that is localhost.localdomain localhost) and Windows has only one. If I want to edit the hosts file in Windows to have the machine name (etest) instead of localhost, I simply replace the word localhost with the machine name I want. The machine need not be part of a domain.In a Linux machine, the two entries localhost.localdomain and localhost seems to indicate that I will need the machine to be part of a domain. Is this true?Can I simply edit both entries to etest so that it will read:127.0.0.1       etest etestor is it required that I substitute one entry with a domain name?Additionally, please let me know what the second line of the /etc/hosts file on the Linux machine is for.::1     localhost6.localdomain6 localhost6hosts file on a Linux machine:# Do not remove the following line, or various programs# that require network functionality will fail.127.0.0.1       localhost.localdomain localhost::1     localhost6.localdomain6 localhost6hosts file on a windows machine:# Copyright (c) 1993-1999 Microsoft Corp.## This is a sample HOSTS file used by Microsoft TCP/IP for Windows.## This file contains the mappings of IP addresses to host names. Each# entry should be kept on an individual line. The IP address should# be placed in the first column followed by the corresponding host name.# The IP address and the host name should be separated by at least one# space.## Additionally, comments (such as these) may be inserted on individual# lines or following the machine name denoted by a '#' symbol.## For example:##      102.54.94.97     rhino.acme.com          # source server#       38.25.63.10     x.acme.com              # x client host127.0.0.1       localhost
Format of /etc/hosts on Linux (different from Windows?)
linux;hosts
You always want the 127.0.0.1 address to resolve first to localhost. If there is a domain you can use that too, but then make sure localhost is listed second. If you want to add aliases for your machine that will lookup to the loopback address you can keep adding them as space separated values on that line. Specifying a domain here is optional, but don't remove localhost from the options.