openstack
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neutron
Code Issues Proposed changes
neutron/neutron/plugins/ml2/drivers/l2pop
History
Yang Li 5301ecf41b Don't add arp responder for non tunnel network port 
When the vlan and vxlan both exist in env, and l2population
and arp_responder are enabled, if we update a port's ip address
from vlan network, there will be arp responder related flows
added into br-tun, this will cause too many arp reply for
one arp request, and vm connections will be unnormal.

Closes-Bug: #1824504
Change-Id: I1b6154b9433a9442d3e0118dedfa01c4a9b4740b
 		2019-04-25 02:34:42 +00:00
..
rpc_manager Removed deprecated class LocalVLANMapping 2016-11-07 20:24:06 +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
db.py Integration of L3HARouterAgentPortBinding in ml2/drivers/l2pop/db.py 2017-11-01 09:31:05 +07:00
mech_driver.py Don't add arp responder for non tunnel network port 2019-04-25 02:34:42 +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