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Re: Is that safe to put public IP directly on Virtual Router/ System VMs?

On 9/26/18 6:21 PM, Netlynker wrote:
Hi Eric,

Usual setup for my other infra service is that we use external firewall
doing NAT and protecting the resource behind. The public IP will stay on
that firewall and it is NATed to private IP of the service internal.

What CS document imply is to put “real” public IP address on System VMs and
VR which will leave those systems exposed directly to outside world.

That is the configuration for a public Cloudstack service. If you are a corporation setting up a private cloud within a corporation, the "public address" should be routed to your corporate network. For example, my corporate "floor" network that goes to the desktops on people's desks is while my corporate "wifi" is I gave my Cloudstack cluster the public address of which is routed to my external firewall router via a VLAN-enabled Cisco Layer 3 switch to the actual firewall on the external DMZ VLAN (Other private networks such as the pool for VPC creation use additional 10.x subnets). The 10.102.x.y addresses are "internet" addresses as far as Cloudstack is concerned -- they can access the Internet. The fact that they're accessing it via my corporate network rather than being directly connected to the Internet is irrelevant.

As far as the safety of the router virtual machines, they are a small Linux distribution just like the one in your external firewall, that, like the one in your external firewall, is configured with routes and firewall rules to be secure. If you were doing a public-facing Internet service there would be no problem putting them directly on the public Internet. From a design perspective they're no more or less secure than your current NAT firewall, which is also a small Linux distribution unless it's a Cisco. Whether you want to put them directly onto the Internet or not depends on your design goals, not safety. If you want to be able to access your virtual machines from the public Internet without logging in via a VPN, such as publicly available services, then a NAT firewall between your Cloudstack service and your virtual machines will not allow for that. If you are satisfied with having your virtual machines only be reachable from your corporate network and comfortable with VPN access for those times you need to access them remotely, then sure, put them on your corporate network behind the NAT firewall. That's what I do, because my production virtual machines providing service to the general public are running on the Amazon cloud, my Cloudstack installation is for corporate-private R&D and support instances that the general public isn't supposed to access.

My question is if that architecture is recommeneded and how safe it is to
put “real” public IP on System VMs and VRs directly.

Thanks in advance,

On Thu, 27 Sep 2018 at 8:58 AM, Eric Lee Green <>

On 9/25/18 6:29 PM, Netlynker wrote:

I looked at the deployment architecture from document and it said to have
public IP addresses on Virtaul Router/System VMs.

Is that recommended setup?

How safe will it be to expose Virtaul Router/ System VMs directly to

If a virtual router is not connected to the Internet, how will it route
traffic from your internal VM's in their virtual private networks to the
Internet? Magic? (This presuming you have an Internet-facing service,
but even if it's internal to your company, the virtual router is going
to need to be able to talk to the Internet via your company's "internal"
Internet network if your internal VM's on their own internal private
networks are going to get to the Internet or other corporate resources).