external network packets to network node

asked 2016-01-15 14:57:37 -0500

aksan gravatar image

I have done a kilo ubuntu installation of openstack. One thing i noticed was the network node's external interface is unnumbered. Then how does the external router forwards the packet to the network node? Suppose a vm has a floating ip . I send a packet to that vm using the floating ip. The nat happens at the network node. How does the packet reached the network node as there is no ip assigned to the interface. I have not configured dvr and l3 agent is running on network node.

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answered 2016-01-15 15:57:07 -0500

dbaxps gravatar image

updated 2016-01-15 16:18:01 -0500

See for instance "Running DVR with External network provider (flat) on CentOS 7.2 RDO Liberty"

When you use external network provider, it creates non-bridged external networking. In this case external interface of neutron router gets built into BR-EX and BR-EX doesn't have IP, which resides on external network

image description
See also :-
DVR with Two external networks via flat network provider on CentOS 7.2 RDO Liberty
This post is addressing question been post on ask.openstack.org some times ago.
Feature mentioned above is not DVR related , see

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Hi dbaxps, How can i view the fip namespace? It is not visible using ip netns. Why qg- port of router namespace is not shown in your diagram ?

aksan gravatar imageaksan ( 2016-01-15 16:33:37 -0500 )edit
dbaxps gravatar imagedbaxps ( 2016-01-15 16:48:46 -0500 )edit

Hi dbaxps, In case of centralized virtual router, which component is responsible for the proxy arp from the physical router?

aksan gravatar imageaksan ( 2016-01-18 22:17:28 -0500 )edit

Ask vendor of your router, why you are asking me ?

dbaxps gravatar imagedbaxps ( 2016-01-19 01:14:23 -0500 )edit

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Asked: 2016-01-15 14:57:37 -0500

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Last updated: Jan 15 '16