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Public and Local network associated to instances? [closed]

asked 2016-12-20 19:50:18 +0300

Nebukazar gravatar image


We have installed vmagine on one of our hyperv host and are trying to do the following use case:

Instances should either have 2 NICs (1x public, 1x local) or just 1 NIC (1x public OR 1x local).

I have been trying to make the public network shared so that the “demo” tenant could use that network but so far, here are the issues I am facing:

  • When selecting only the public network, I get the proper public IP from the public’s subnet, but I am unable to ping the outside;
  • When I select both network (public and private) I only get the public network interface configured on the guest, no private interface is being shown up and still unable to ping the outside;
  • When I select only the local network, I’m getting a local IP from the local network and I’m able to reach the outside.

Floating IP is working fine, however, I’d like to get the public IP directly configured on the instance due to some compatibility issues we might be experiencing (software side).

Do you guys have any ideas on how to achieve this ?


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Closed for the following reason the question is answered, right answer was accepted by Nebukazar
close date 2017-01-23 23:17:34.971610

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answered 2016-12-20 20:49:47 +0300

alexpilotti gravatar image

The general idea in OpenStack is that Neutron manages L3 routing, allowing security groups (firewall), load balancing and other L3 features available via SDN solutions (OVS and Hyper-V networking in our case).

Here's the “usual OpenStack way” to have a VM connected to 2 networks, one internal and one external:

  • Create a new network in your tenant (demo or else, not admin), call it e.g. "local". Do not attach it to a router.
  • Boot a VM with two nics: one on "private" and one on "local"

The first NIC on “private” will be natted and routed externally through “public”. The second NIC on “local” will be internal only (not routed).

Said that, there’s also an alternative (which I wouldn't recommend, but it's good to know it's available):

  • create a Neutron flat network associated to an external switch on your hyper-v host (needs a network_provider mapping).
  • Boot a VM attached to that network using fixed IPs (unless you want to let Neutron handle the DHCP on your physical network)

This way the VM will skip completely the Neutron routing and be directly connected to your physycal network.

here's an example on how to do the Neutron side of the configuration:

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Asked: 2016-12-20 19:50:18 +0300

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Last updated: Dec 20 '16