neutron/neutron/plugins/ml2/drivers/l2pop
Kevin Benton 9016c1f810 l2pop: check port mac in pre-commit to stop change
Check that a port mac address hasn't changed during the precommit
phase of the port update rather than the post commit so the resulting
exception actually stops it from happening.

Change-Id: I62f120b3c954fa4251a7d676cf2c623e6da5a98b
Closes-Bug: #1486379
2015-08-19 22:56:52 -07:00
..
rpc_manager Restructure agent code in preparation for decomp 2015-06-26 15:06:49 +00:00
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 oslo: migrate to namespace-less import paths 2015-02-05 15:09:32 +01:00
constants.py Remove @author(s) from copyright statements 2014-09-15 21:40:09 +09:00
db.py l2-pop shouldn't notify agent about inactive ports 2015-02-06 08:47:55 -08:00
mech_driver.py l2pop: check port mac in pre-commit to stop change 2015-08-19 22:56:52 -07:00
rpc.py Migrate to oslo.log 2015-03-12 11:22:56 +01:00

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