On CentOS 7 minimal installation on a OpenVZ VPS, ifconfig was missing. You can install ifconfig with yum

yum -y install net-tools

To see which package provide “ifconfig” command, run

[root@cloud1 ~]# yum whatprovides "*bin/ifconfig"
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirror.anl.gov
 * epel: epel.mirror.constant.com
 * extras: mirror.cogentco.com
base/7/x86_64/filelists_db     
net-tools-2.0-0.17.20131004git.el7.x86_64 : Basic networking tools
Repo        : base
Matched from:
Filename    : /sbin/ifconfig



net-tools-2.0-0.17.20131004git.el7.x86_64 : Basic networking tools
Repo        : @base
Matched from:
Filename    : /sbin/ifconfig



[root@cloud1 ~]#