For example, Assume there is no ifconfig command on CentOS.
# ifconfig
command not found
Then, run yum command like this...
# yum provides ifconfig
....
....
net-tools-2.0-0.17.20131004git.el7.x86_64 : Basic networking tools
Repo : base
Matched from:
Filename : /sbin/ifconfig
# yum install net-tools