FORWARD rules for public network
CentOS7 comes with pre-defined REJECT rule in FORWARD chain
that doesn't allow to access external networks from public
When deploying ISO with virtualbox scripts slave nodes are trying
to connect to external networks via public net, with default
gateway on master node. However, they can't establish a connection
because there is no explicit rule in FORWARD chain to allow it,
so they are rejected.
This commit adds rules to allow connection to ext networks in
Compatible with CentOS6 & CentOS7 master node.