1. Software OpenFlow Solutions using Open vSwitch
Ryan Izard

2. Open vSwitch (OVS) Software OpenFlow switch Documentation and code
Production quality
Open source
Documentation and code
Kernel and userspace modes
Supports
Monitoring: Netflow, sFlow, SPAN, RSPAN
Control: OpenFlow, OVSDB

3. OpenFlow Support Supports OpenFlow 1.0 through 1.5
Suggest OVS >= 2.4.0
Meter protocol support
Limited 1.5 support
Consult the change logs when in doubt
ofsoftswitch supports meters
Can daisy-chain with OVS

4. How to use OVS? General Instructions For GENI Download OVS Install OVS
Start OVS daemons
Configure OVS bridges
Connect controller to OVS bridges
Install flows and control your network
Start with an OVS image
Ubuntu 12 or 14
Configure OVS bridges
Connect controller to OVS bridges
Install flows and control your network

5. Select OVS Image in GENI using the Jacks GUI
Node Type: “emulab-xen”
Disk Image: “Ubuntu 14 with OVS, by Niky”

6. Before We Get Started For this guide
<…> indicates variable substitution
[…] indicates an optional parameter
…|… indicates a exclusive-or between two parameters
You must be root for any ovs-* command

7. OpenFlow Version Support
OVS w/OpenFlow version > 1.0
Must use “-O OpenFlow<ver>” flag for any ovs-ofctl cmd
Include flag at end of command
Note capital O, not zero
Examples
OpenFlow 1.0, <ver> = 10, e.g. “-O OpenFlow10”
OpenFlow 1.1, <ver> = 11, e.g. “-O OpenFlow11”
OpenFlow 1.2, <ver> = 12, e.g. “-O OpenFlow12”
OpenFlow 1.3, <ver> = 13, e.g. “-O OpenFlow13”
OpenFlow 1.4, <ver> = 14, e.g. “-O OpenFlow14”
OpenFlow 1.5, <ver> = 15, e.g. “-O OpenFlow15”

8. Creating and Viewing a Bridge
Add/remove a bridge
$ ovs-vsctl add-br <bridge-name>
$ ovs-vsctl del-br <bridge-name>
Add/remove a port to/from a bridge
$ ovs-vsctl add-port <bridge> <port-name>
$ ovs-vsctl del-port <bridge> <port-name>
Show general configuration
$ ovs-vsctl show
Show detailed switch configuration
$ ovs-ofctl show <bridge-name>

9. Datapath and Controller
Set datapath ID (DPID)
$ ovs-vsctl set bridge <bridge-name> \
other-config:datapath-id=
Set OpenFlow version
protocols=OpenFlow<ver>,OpenFlow<ver>,…
Set controller
$ ovs-vsctl set-controller <bridge-name> \
tcp:<controller-ip>:<controller-port>
Also supports SSL (tutorial)

10. Fail Modes Perform learning switch if controller disconnects
$ ovs-vsctl set-fail-mode <bridge-name> standalone
Only use installed flows if controller disconnects
$ ovs-vsctl set-fail-mode <bridge-name> secure

11. Debugging View OpenFlow channel b/t controller and switch
$ ovs-vsctl snoop <bridge-name>
$ ovs-vsctl monitor <bridge-name>

12. Table Operations
Typically done by controller, but useful when debugging or for testing
For full documentation, see ovs-ofctl man page
Show flow table entries
$ ovs-ofctl dump-flows <bridge-name>
Add an entry to flow table
$ ovs-ofctl add-flow [<priority>] [<table-id>] [<cookie>] \
<matches> [<actions> | <instructions>]
Remove an entry from a flow table
$ ovs-ofctl del-flow [--strict] <priority> <table-id> \
[<cookie>] <matches> ]

13. Table Operations Modify a flow table entry
$ ovs-ofctl mod-flow [--strict] <priority> <table-id> \
[<cookie>] <matches> [<actions> | <instructions>]
Can also set cookie and other flow fields
Can also add, remove, modify, show groups and buckets
ovs-ofctl add-group, del-group, mod-group, dump-groups, insert-buckets, remove-buckets
Consult ovs-ofctl docs for details

14. Spanning Tree Enable/disable Configure priority (for root election)
$ ovs-vsctl set bridge <bridge-name> stp_enable=true
$ ovs-vsctl set bridge <bridge-name> stp_enable=false
Configure priority (for root election)
$ ovs-vsctl set bridge <bridge-name> \
other_config:stp-priority=0x<some-hex-value>
Configure per-port path cost
$ ovs-vsctl set port <port-name> \
other_config:stp-path-cost=<some-decimal-value>

15. Allow Host to TX/RX Packets
LOCAL port of OVS is network interface
e.g. LOCAL <--> br0
can route into iface

16. Example Workflow To turn an example machine into a switch:
switch$ ovs-vsctl add-br br0
switch$ ovs-vsctl add-port br0 eth1
switch$ ovs-vsctl add-port br0 eth2
switch$ ovs-vsctl set-controller tcp: :6653
switch$ ifconfig br /24 up # “host” on LOCAL port
switch$ ping # assume host-2 out eth2
switch$ ping # assume host-1 out eth1
and on host-1 and host-2, respectively, will also be able to communicate through the OVS bridge br0 on the switch node

17. Give it a Try Yourself
Tutorial