I followed the steps mentioned at https://spredzy.wordpress.com/2013/11/22/enable-network-namespaces-in-centos-6-4/. But it doesn't seem to help. I'm still getting this error -
[root@localhost app]# ip netns
Object "netns" is unknown, try "ip help".
Can anyone help me in enabling Linux Namespaces in Centos 6.5?
iproute-2.6.32-130.el6ost.netns.2.x86_64
Installing this rpm solved it.