openstack team mailing list archive

[Ahmed Al-Mehdi <ahmed@xxxxxxxxxx>]

From: gong yong sheng <gongysh@xxxxxxxxxxxxxxxxxx<mailto:gongysh@xxxxxxxxxxxxxxxxxx>>
Date: Wednesday, November 21, 2012 5:25 PM
To: Ahmed Al-Mehdi <ahmed@xxxxxxxxxx<mailto:ahmed@xxxxxxxxxx>>
Cc: "openstack@xxxxxxxxxxxxxxxxxxx<mailto:openstack@xxxxxxxxxxxxxxxxxxx>" <openstack@xxxxxxxxxxxxxxxxxxx<mailto:openstack@xxxxxxxxxxxxxxxxxxx>>
Subject: Re: [Openstack] Quantum networking question..

On 11/22/2012 08:23 AM, Ahmed Al-Mehdi wrote:
Hello,

I have a question about setting up Quantum, following the steps described by Bilel Msekni ( https://github.com/mseknibilel/OpenStack-Folsom-Install-guide/blob/master/OpenStack_Folsom_Install_Guide_WebVersion.rst ), which uses 3 NICs.
(Similar document/setup is also described by OpenStack.org also -  https://review.openstack.org/#/c/16096/ )

Based on the node diagram in Bilel's document, I understand why eth0 needs an IP address that is accessible to internet.    However,
 - Why does eth1 need an IP address, since it will be used for VM network?
 - Why does eth2 not need an IP address (set to 0.0.0.0) since it is connected to the internet.

In my setup, I set an IP address to eth0 through my corp. DHCP server.  Can I similarly assign an IP address to the other eth port (be it 1 or 2) that needs connection to the internet?

eth1 should not have IP since it will be added into br-eth1. If you want eth1 have IP, you can move the ip to br-eth1:
sudo ip addr <ip> dev br-eth1
sudo ifconfig br-eth1 up
eth2 is connected to br-ex bridge. If u don't need the host to access the internet via eth2, there is no need to assign an IP to eth2 or br-ex
the VM's will be able to access the internet via br-ex, which is via eth2 in turn to access internet.

You can assign an IP to br-ex so that your host can use it.
Thank you,
Ahmed.




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Thank you for your response/comments.  I understand what you are saying, logically makes pretty good sense.  However, my questions were geared towards understanding why the eth ports on the controller-node is configured the way they are as per the document/diagram.  Per the description, it seems the setup is done so the VMs  will have internet access, so why is no IP assigned to eth2.  And why is an IP address assigned to eth1, and where did the IP address come from.  Is there some typo in the document (which I really doubt) or most probably lack of understanding on my part.

Regards,
Ahmed.