Open Stack

Dmitry Makovey wrote:
> first of all - thank you very much for bearing with me on this one.;)

My pleasure, happy to help!

> So how shall I go about setting it up? do I need to spin up some
> "dual-nic" VM that would act as a router or can I use some other
> OpenStack facilities for that?

You won't need a dual NIC VM, but rather to just add a route on each VM 
that tells it that, for hosts which have addresses in the other 
network(s), to not use the default gateway (which is the ext_net 
attached router), but to send their traffic via the other ('private') 
router's interface.

So, for example on the instance which you have attached to the 
'private_gb_db_net' network you would have two routes:

* ip route add -net 10.10.31.0 netmask 255.255.255.0 gw 10.10.10.4

* ip route add -net 10.10.25.0 netmask 255.255.255.0 gw 10.10.10.6

As of now, the default gateway is the only route they know of, so while 
it is true that the Neutron routers themselves have automatic knowledge 
of their attached networks, that is separate from the instance's 
knowledge of which routers are available.

I hope that helps.

Regards,

Richard