OpenStack nova/neutron iptables rules are cleared when implementing host rules

Issue

• What is the preferred way to manage iptables rules for the host along with the dynamic rules from nova and neutron?
• We have a local firewall policy on our OpenStack hosts which lock down communication at a host level.
• We've noticed that if we make changes to this policy and restart iptables that any dynamic rules created by nova or neutron are lost during that restart.