The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
The /etc/hosts file associates host names
with IP addresses. It allows the system to look up
(resolve) the IP address of a host given its
name, or the name given the UP address. Most networks use DNS
(Domain Name Service) to perform address or name resolution.
Even if your network uses DNS, it is usual to include lines in
this file that specify the IPv4 and IPv6 addresses of the
loopback device, for example:
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
The first and second column contains the IP address and host name. Additional columns contain aliases for the host name.
For more information, see the hosts(5) manual
page.