neutron/neutron/plugins/ml2/drivers/l2pop
Brian Haley 08a60f7483 Remove usage of six.add_metaclass
With python 3.x, classes can use the metaclass= logic
to not require usage of the six library.

One step in removing all of six usage from neutron.

Change-Id: I2f815e412d9a96eb5faf2b3bb3a1e393a9db9309
2020-05-21 14:41:18 -04:00
..
rpc_manager Remove usage of six.add_metaclass 2020-05-21 14:41:18 -04:00
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
db.py Fix pep8 E128 warnings in non-test code 2019-03-12 21:22:33 +00:00
mech_driver.py ovs agent: signal to plugin if tunnel refresh needed 2020-01-09 14:18:43 +00:00
rpc.py remove neutron.common.rpc 2019-02-06 11:05:55 -07:00

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