Regarding how to disable source-check ala AWS instance on openstack

openstack-ip-source-check.txt

Asked and answered here: 

https://ask.openstack.org/en/question/51392/neutron-openvswitch-port-how-to-disable-source-ip-address-checking/

In short, there are "allowed-address-pairs" that can alternatively used to solve such a problem.

Some scenario like: 

- An instance has two ports in two different subnet, one belong in e.g. 10.1.1.123 (eth0) 
  and the other one in 10.1.2.223 (eth1).
- This instance will act as router between the two network without NAT involved.
- To be able to pass packet came from 10.1.2.0/24 to net 10.1.1.0/24 we can set the port to use "allowed_address_pairs", e.g.

    neutron port-update --allowed-address-pairs ip_address=10.1.2.0/24 <port-id-of-eth0>

Need to check and investigate this futher later on.