openstack
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neutron
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neutron/neutron/plugins/ml2/drivers/l2pop
History
venkata anil 89cd4d07d1 Rename dvr portbinding functions 
As part of making DVR portbinding implementation generic, we rename
dvr portbinding functions as distributed portbinding functions.
In next patch we make dvr logic for port binding generic,
to be useful for all distributed router ports(for example, HA).

Partial-Bug: #1595043
Partial-Bug: #1522980
Change-Id: I402df76c64299156d4ed48ac92ede1e8e9f28f23
 		2016-07-09 08:21:17 +00:00
..
rpc_manager Classes lack metaclass decoration 2016-05-05 13:31:15 -06:00
README Implement local ARP responder onto OVS agent 2014-05-19 21:42:11 +02:00
__init__.py Empty files should not contain copyright or license 2014-10-20 00:50:32 +00:00
config.py Use _ from neutron._i18n 2015-12-06 19:39:04 +09:00
db.py Rename dvr portbinding functions 2016-07-09 08:21:17 +00:00
mech_driver.py Rename dvr portbinding functions 2016-07-09 08:21:17 +00:00
rpc.py Get rid of marshall_fdb_entries 2016-02-03 00:16:45 -08:00

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