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Creating a network without NAT in essex

asked 2013-04-29 13:04:25 -0500

jzwiep gravatar image

updated 2013-04-29 13:10:40 -0500

We're looking for a way to configure OpenStack so that it assigns ip addresses from a given subnet of our internal network without any NAT rules in place.

Currently we use a similar setup as outlined here:

It essentially disables nova-network, and allows an external DHCP server to assign ip addresses to the instances. This works, but it breaks major functionality within OpenStack (like parts of the api, and metadata) and it makes using the system a pain.

Is a NAT free network possible under essex?

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answered 2013-05-10 21:51:14 -0500

fifieldt gravatar image has the following information from a nova developer:

If you are attempting to stop nova-network from snatting for instances you can very easily do it with conf:


(set routingsourceip to none)

This will stop the snat for instances. Please note that you will need to provide a gateway through dnsmasq for your instances to reach the internet.

However, I am not sure if it works on Essex, or if it will entirely meet your needs - please let us know :)

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Hmm, yeah. I'm not sure this fixes our problem. Thanks though.

jzwiep gravatar imagejzwiep ( 2013-05-17 19:59:55 -0500 )edit

answered 2013-07-24 21:01:53 -0500

jzwiep gravatar image

These nova.conf network options, specifically the dmz_cidr solved the issue:

# network specific settings

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Asked: 2013-04-29 13:04:25 -0500

Seen: 267 times

Last updated: Jul 24 '13