Role of "br-int" in neutron GRE networking

asked 2015-04-06 06:31:23 -0500

deepa gravatar image


 Recently I installed openstack 3 node setup and trying to understand functionality of each OVS bridge, openstack services and other components.

I understood that br-int will forward a outbound packet to aparticular VM on compute node but dont find any rule ovs do to the same. It will be helpful if someone can provide insight into role of br-int on both network and compute node

Thanks, Deepa.

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Hi Deepa. I m also trying to setup Juno multi node setup.but got error server is incapable of serving request when I was creating instance.please share how you did it.which docs u followed.

Amitabh Sinha gravatar imageAmitabh Sinha ( 2015-04-06 12:11:29 -0500 )edit

Hi Amitabh, I have followed link to install three node juno setup. Please check your admin credentials once for created network and services. I followed as it without any changes. Please provide error log detail

deepa gravatar imagedeepa ( 2015-04-07 04:38:14 -0500 )edit

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answered 2015-04-06 06:43:25 -0500

Hi, here is two links with more information about how neutron works.

Networking in too much detail

Neutron packet flows notes handout

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Thanks Eduardo . I have already gone through both these link but still not clear with respect to how the packet reached a particular VM. On compute node I found all VM in same private network are tag with same vlan at 'br-int" OVS bridge. Does it the linux datapath which maintain L2/L3 table ?

deepa gravatar imagedeepa ( 2015-04-06 07:05:07 -0500 )edit

I've been investigating a little more about GRE tunnels and found this post that I think answers your question

Gre tunnels in Openstack Neutron

Eduardo Gonzalez gravatar imageEduardo Gonzalez ( 2015-04-06 08:35:56 -0500 )edit

Thanks Edurado . It helped in better understanding of GRE based networking but I still didnt find how to check the Learned MAC address on 'br-int'. Which command can be used to check the same

deepa gravatar imagedeepa ( 2015-04-07 04:32:33 -0500 )edit

I got the command to check br-int learned MAC address- "ovs-appctl -t ovs-vswitchd fdb/show br-int"

Thanks Eduardo for good references for better understanding

deepa gravatar imagedeepa ( 2015-04-07 06:10:46 -0500 )edit

answered 2015-04-07 06:11:08 -0500

deepa gravatar image

I got the command to check br-int learned MAC address- "ovs-appctl -t ovs-vswitchd fdb/show br-int"

Thanks, Deepa.

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Hi Deepa, Can you please help me in networking things...I have configured everything such as controller, compute and network node without any error...but i am unable to communicate external (public) network but able to communicate internal (private) network within openstack.

Kishore Devkate gravatar imageKishore Devkate ( 2015-07-20 05:41:09 -0500 )edit

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Asked: 2015-04-06 06:31:23 -0500

Seen: 1,602 times

Last updated: Apr 07 '15