[Openstack] How to make DevStack install OpenStack with Neutron?

Mark Kirkwood mark.kirkwood at catalyst.net.nz
Tue Oct 7 06:50:01 UTC 2014

On 07/10/14 19:44, Mike Spreitzer wrote:
> Mark Kirkwood <mark.kirkwood at catalyst.net.nz> wrote on 10/07/2014
> 02:23:36 AM:
>  > I think why this is not documented is the usual use-case for devstack is
>  > development setups where real external ips for the VMs is usually not a
>  > point of interest.
>  >
>  > For instance I never need this...I do sometimes want the VMs to be able
>  > to access the internet, and that is pretty easy:
>  >
>  > $ sudo sysctl -w net.ipv4.ip_forward=1
>  > $ sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
>  >
>  > For access the other way, yes it's more complex. As others have posted,
>  > you need real ip ranges available in your external network and
>  > (probably) an additional nic in your test box that can be
>  > designated/mapped as br-ex
>  > so that the various routers/gateways in the neutron setup use it.
> Thanks, Mark.  As I mentioned in my original post, I have a block of IP
> addresses that I can use as I see fit --- I have a subnet that I
> control.  I do not see why an additional NIC on the host would be
> needed, it already has a NIC connected to a subnet that I control (I am
> trying to make it easy here).

True, you can just assign another ip to your nic (in the appropriate 
subnet range) and use that as br-ex - yes, I'm being old fashioned and 
would prefer another nic to make it clear to me what was happening :-)

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