[Openstack-operators] VM with a public IP

Narayan Desai narayan.desai at gmail.com
Mon Aug 13 23:02:20 UTC 2012

On Mon, Aug 13, 2012 at 4:55 PM, Paul Walton <paul.d.walton at gmail.com> wrote:
> Unfortunately, I do not manage the network, and do not have access to the
> DHCP server.  This means that I do not have a subnet of IPs that I can
> simply hand out freely to my VMs.  If I want a VM to have a public IP then
> it must make a request to the campus DHCP server.  There are special cases
> where I can assign static IPs to servers, but this is infeasible for the
> majority of the VMs I will create since they will be used by students to
> complete assignments in class, and will only exist during the course of a
> semester.
> So, as I understand things so far, OpenStack assumes that I have my own
> subnet of public IPs that I can freely use for my VMs?  I can't imagine this
> being a reasonable design assumption to make on their part.  Perhaps I'm
> overlooking something?

The use model for external IP addresses is that they can be allocated
and deallocated from projects on a relatively infrequent basis (ie
address to project allocations last a long time, so that users can
count on the external addresses not changing.)

I'm not sure how IP addresses managed by external DHCP services could
fit into this model robustly (ie they could disappear out from under
you at any time). You could hack something up that leases and renews
ip addresses on a long term basis, but this would definitely be a

More information about the OpenStack-operators mailing list