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neutron/neutron/plugins/ml2/drivers/l2pop
History
Ihar Hrachyshka b43307b768 Moved rpc_compat.py code back into rpc.py 
Most of this code will probably stay with us for quite some time, so
let's make things easier and consider them as our way of doing RPC.

blueprint oslo-messaging

Change-Id: Iaf353b23f9c54b82d1e02a6bd5a5960cec827c88
 		2014-06-24 10:35:39 +02:00
..
README Implement local ARP responder onto OVS agent 2014-05-19 21:42:11 +02:00
__init__.py Add l2 population base classes 2013-09-12 01:06:51 +02:00
config.py Add l2 population base classes 2013-09-12 01:06:51 +02:00
constants.py Vxlan / L2population support to Linuxbridge Agent 2013-09-12 02:51:37 +02:00
db.py Enable flake8 E711 and E712 checking 2014-04-09 23:03:57 -04:00
mech_driver.py Don't instantiate RPC clients on import 2014-06-17 21:56:24 +02:00
rpc.py Moved rpc_compat.py code back into rpc.py 2014-06-24 10:35:39 +02:00

README 

Neutron ML2 l2 population Mechanism Drivers

l2 population (l2pop) mechanism drivers implements the ML2 driver to improve
open source plugins overlay implementations (VXLAN with Linux bridge and
GRE/VXLAN with OVS). This mechanism driver is implemented in ML2 to propagate
the forwarding information among agents using a common RPC API.

More informations could be found on the wiki page [1].

VXLAN Linux kernel:
-------------------
The VXLAN Linux kernel module provide all necessary functionalities to populate
the forwarding table and local ARP responder tables. This module appears on
release 3.7 of the vanilla Linux kernel in experimental:
- 3.8: first stable release, no edge replication (multicast necessary),
- 3.9: edge replication only for the broadcasted packets,
- 3.11: edge replication for broadcast, multicast and unknown packets.

Note: Some distributions (like RHEL) have backported this module on precedent
      kernel version.

OpenvSwitch:
------------
The OVS OpenFlow tables provide all of the necessary functionality to populate
the forwarding table and local ARP responder tables.
A wiki page describe how the flow tables did evolve on OVS agents:
- [2] without local ARP responder
- [3] with local ARP responder. /!\ This functionality is only available since
                                    the development branch 2.1. It's possible
                                    to disable (enable by default) it through
                                    the flag 'arp_responder'. /!\


Note: A difference persists between the LB and OVS agents when they are used
      with the l2-pop mechanism driver (and local ARP responder available). The
      LB agent will drop unknown unicast (VXLAN bridge mode), whereas the OVS
      agent will flood it.

[1] https://wiki.openstack.org/wiki/L2population_blueprint
[2] https://wiki.openstack.org/wiki/Ovs-flow-logic#OVS_flows_logic
[3] https://wiki.openstack.org/wiki/Ovs-flow-logic#OVS_flows_logic_with_local_ARP_responder