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b33951b80f
The OpenFlow port change detection code in update_port() is supposed to send out an OFPT_PORT_STATUS message whenever an OpenFlow port is added or removed or changes in some way. This commit fixes a number of bugs that have persisted until now. First, if a port with a given name is removed from the datapath and a new port with the same name but a different port number is added to the datapath, then update_port() would report this as a port "modify" change. Reporting this as a "modify" seems likely to confuse controllers, which have no reason to realize that the old port was deleted and may not understand why a port that has not been reported as added would be modified. (This scenario is more likely than before, because the Linux datapath implementation no longer quickly reuses port numbers. This problem has actually been reported in testing.) This commit fixes the problem by changing update_port() to report a "delete" of the old port followed by an "add" of the new port. Second, suppose that a datapath initially has "eth1" on port 1 and "eth2" on port 2. Then, "eth1" gets removed and "eth2" is reassigned to port 1. If update_port() is first passed "eth2", then the old implementation would have sent out an OpenFlow "modify" notification instead of "delete" followed by "add", which is the same as the previous scenario. But as a further wrinkle, it would have failed to remove "eth1", which meant that we ended up with two "ofports" with port number 1! This commit fixes this problem too. Reported-by: David Tsai <dtsai@nicira.com> Bug #5466. NIC-372.
Open vSwitch <http://openvswitch.org>
What is Open vSwitch?
---------------------
Open vSwitch is a multilayer software switch licensed under the open
source Apache 2 license. Our goal is to implement a production
quality switch platform that supports standard management interfaces
and opens the forwarding functions to programmatic extension and
control.
Open vSwitch is well suited to function as a virtual switch in VM
environments. In addition to exposing standard control and visibility
interfaces to the virtual networking layer, it was designed to support
distribution across multiple physical servers. Open vSwitch supports
multiple Linux-based virtualization technologies including
Xen/XenServer, KVM, and VirtualBox.
The bulk of the code is written in platform-independent C and is
easily ported to other environments. The current release of Open
vSwitch supports the following features:
* Standard 802.1Q VLAN model with trunk and access ports
* NIC bonding with or without LACP on upstream switch
* NetFlow, sFlow(R), SPAN, RSPAN, and ERSPAN for increased visibility
* QoS (Quality of Service) configuration, plus policing
* GRE, GRE over IPSEC, and CAPWAP tunneling
* 802.1ag connectivity fault management
* OpenFlow 1.0 plus numerous extensions
* Transactional configuration database with C and Python bindings
* Compatibility layer for Linux bridging code
* High-performance forwarding using a Linux kernel module
The included Linux kernel module supports Linux 2.6.18 and up, with
testing focused on 2.6.32 with Centos and Xen patches. Open vSwitch
also has special support for Citrix XenServer hosts.
Open vSwitch can also operate, at a cost in performance, entirely in
userspace, without assistance from a kernel module. This userspace
implementation should be easier to port than the kernel-based switch.
It is considered experimental.
What's here?
------------
The main components of this distribution are:
* ovs-vswitchd, a daemon that implements the switch, along with
a companion Linux kernel module for flow-based switching.
* ovsdb-server, a lightweight database server that ovs-vswitchd
queries to obtain its configuration.
* ovs-brcompatd, a daemon that allows ovs-vswitchd to act as a
drop-in replacement for the Linux bridge in many environments,
along with a companion Linux kernel module to intercept bridge
ioctls.
* ovs-dpctl, a tool for configuring the switch kernel module.
* Scripts and specs for building RPMs that allow Open vSwitch
to be installed on a Citrix XenServer host as a drop-in
replacement for its switch, with additional functionality.
* ovs-vsctl, a utility for querying and updating the configuration
of ovs-vswitchd.
* ovs-appctl, a utility that sends commands to running Open
vSwitch daemons.
* ovsdbmonitor, a GUI tool for remotely viewing OVS databases and
OpenFlow flow tables.
Open vSwitch also provides an OpenFlow implementation and tools for
those interested in OpenFlow but not additional Open vSwitch features:
* ovs-openflowd, an alternative to ovs-vswitchd that implements a
simple OpenFlow switch, without the special features provided by
ovs-vswitchd.
* ovs-controller, a simple OpenFlow controller.
* ovs-ofctl, a utility for querying and controlling OpenFlow
switches and controllers.
* ovs-pki, a utility for creating and managing the public-key
infrastructure for OpenFlow switches.
* A patch to tcpdump that enables it to parse OpenFlow messages.
What other documentation is available?
--------------------------------------
To install Open vSwitch on a regular Linux machine, read INSTALL.Linux.
To use Open vSwitch as a drop-in replacement for the Linux bridge,
read INSTALL.bridge.
To build RPMs for installing Open vSwitch on a Citrix XenServer host
or resource pool, read INSTALL.XenServer.
To use Open vSwitch with KVM on Linux, read INSTALL.Linux, then
INSTALL.KVM.
To install Open vSwitch without using a kernel module, read
INSTALL.userspace.
To learn how to set up SSL support for Open vSwitch, read INSTALL.SSL.
Each Open vSwitch userspace program is accompanied by a manpage. Many
of the manpages are customized to your configuration as part of the
build process, so we recommend building Open vSwitch before reading
the manpages.
Contact
-------
bugs@openvswitch.org
http://openvswitch.org/