What configuration file is used to tell Linux which system to use for name resolution authentication etc?
Name resulution can be provided statically with /etc/hosts which
usually contains IP addresses along with corresponding domain
names, like:
127.0.0.1 localhost localhost.localdomain
127.0.0.2 test.localhost
or dynamically, by performing requests to name servers specified
in /etc/resolv.conf .
Authentication data for local users is held within several
files: /etc/group which contains list of existing groups and
memberships, /etc/passwd which contains list of existing users and
their attributes like home directory and, if the system has been
configured to utilize shadow passwords, /etc/shadow which contains
encrypted passwords along with additional account attributes like
expiration time.