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openstack 2 network interfaces requirement

asked 2016-10-08 15:33:56 -0500

laurentiusoica gravatar image


For all OpenStack setups I've followed there is a common requirement to have at least 2 NICs on the controller and compute nodes.

One for management and one public.

What's the reason for this requirement ? Is it possible to do an OpenStack setup with one interface only (for controller and compute nodes) ?

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answered 2016-10-09 01:40:49 -0500

dbaxps gravatar image

updated 2016-10-09 01:42:13 -0500

In case Controller/Network Node && N*Compute Node Setup
Compute :

NIC2 - VXLAN (GRE) either VLAN connectivity to Controller


NIC2 - VXLAN (GRE) either VLAN connectivity to Compute
NIC3 - External Network

Using same NICs for MGMT and VXLAN tunnelling is good only for POC deployments.

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Thanks. I'm trying to understand why mixing management and external traffic is a bad idea. Why do you say "PoC deployments" only ?

laurentiusoica gravatar imagelaurentiusoica ( 2016-10-09 06:17:11 -0500 )edit

I told mixing MGMT and internal tunnelling is bad idea. Network Congestion. Standard ingress/egress routing is done via Controller ( unless you go to DVR ) . Mixing MGMT && External would cause lack of security

dbaxps gravatar imagedbaxps ( 2016-10-09 06:22:46 -0500 )edit

Why do you say "PoC deployments" only ?
If you are not happy with your job it would work fine, forcing you to look for new position.

dbaxps gravatar imagedbaxps ( 2016-10-09 06:25:07 -0500 )edit

That's not the point, Boris. It's just understanding the requirements: I have a few physical machines used for development purposes. I plan to move them to a private OS cloud. This is to get a better allocation of H/W, faster response time in terms of development infra requirements and so on.

laurentiusoica gravatar imagelaurentiusoica ( 2016-10-09 13:41:04 -0500 )edit

Now, the machines already have a management network so getting access to a terminal is guaranteed. The only issue I see is that in case N/W congestion there is an impact on OS services and their dependencies (MariaDB , MongoDB, RabbitMQ, Apache server).

laurentiusoica gravatar imagelaurentiusoica ( 2016-10-09 13:41:24 -0500 )edit

answered 2016-10-09 00:45:15 -0500

rikesh gravatar image

Usually one NIC for management network and one NIC for the external network used. Hope that helps...

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Asked: 2016-10-08 15:33:56 -0500

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Last updated: Oct 09 '16