介紹 OpenvSwitch Componets 和 debugging OpenvSwitch

1. meetup #2
OpenvSwitch 初探pichuang@sdnds-tw

2. About me
❖ pichuang a.k.a. ⼩小⾶飛機!
❖ 救⽕火員型研究⽣生!
❖ NCTU CSCC TA!
❖ NCTU Wireless Internet Lab!
❖ http://roan.logdown.com!
❖ http://fbl.me/pichuang

3. OpenvSwitch Introduction
❖ Production Quality!
❖ Multi Layer virtual switch!
❖ L2 - L4!
❖ Support OpenFlow protocol!
❖ Written in platform-independent C

4. OpenvSwitch Features
❖ VLAN tagging and trunking (802.1q)!
❖ Standard Spanning Tree Protocol (802.1d)!
❖ Link Aggregation Control Protocol (802.3ad)!
❖ Port mirror!
❖ RSPAN!
❖ SPAN

5. ❖ Flow monitor!
❖ sFlow!
❖ NetFlow!
❖ IP Flow Information Export (IPFIX)!
❖ QoS Control!
❖ Tunneling Protocol!
❖ VXLAN!
❖ GRE!
❖ IPSEC!
❖ Support Intel® DPDK!
❖ Support Linux Kenrel 3.11 ~ 3.14

6. OpenvSwitch Overview
OpenFlow Controller
Remote
User space
OpenFlow protocol
ovs-vswitchd ovsdb-server
datapath!
ovs kernel module
Kernel space
unix socket
netlink

7. kmod_openvswitch
OpenFlow Controller
Remote
User space
OpenFlow protocol
ovs-vswitchd ovsdb-server
datapath!
ovs kernel module
Kernel space
unix socket
netlink

8. ❖ a.k.a “datapath"!
❖ Fast Path lookup!
❖ Strict match!
❖ Similar to linux bridge !
❖ Hook network device handle!
❖ Extract Flow key!
❖ jhash3!
❖ Implement tunneling
protocol!
❖ Megaflow (Wildcard table)

9. ovs-dpctl
❖ Manage datapath command!
❖ ovs-dpctl show!
❖ ovs-dpctl dump-flows!
❖ ovs-dpctl add-flow!
❖ ovs-dpctl -h!
!
❖ ovs-dpctl-top (python)

10. ovs-vswitchd
OpenFlow Controller
Remote
User space
OpenFlow protocol
ovs-vswitchd ovsdb-server
datapath!
ovs kernel module
Kernel space
unix socket
netlink

11. ❖ OpenvSwitch core component!
❖ Talk to datapath via netlink!
❖ Communicate with ovsdb-server via unix socket!
❖ Implement various protocols!
❖ like OpenFlow protocol!
❖ Include exactly table(Fast lookup) and wildcard table
(Slow lookup)

12. ovs-ofctl
❖ Manage ovs-vswitchd command!
❖ ovs-ofctl dump-flows <bridge name>!
❖ ovs-ofctl show <bridge name>!
❖ ovs-ofctl dump-tables <bridge name>!
❖ ovs-ofctl -h

13. ovs-appctl
❖ Manage logging level!
❖ ovs-appctl vlog/list!
❖ ovs-appctl vlog/set {module name}:{console, syslog,
file}:{off, emer, err, warn, info, dbg}!
❖ Generate packet for trace!
❖ ovs-appctl ofproto/trace <bridge name>!
❖ http://goo.gl/tWbZXH

14. ovsdb-server
OpenFlow Controller
Remote
User space
OpenFlow protocol
ovs-vswitchd ovsdb-server
datapath!
ovs kernel module
Kernel space
unix socket
netlink

15. ❖ ovs-vswitchd configuration is stored on disk!
❖ The OVSDB management protocol (RFC 7047)!
❖ vswitch.ovsschema!
❖ JSON Format

16. ovs-vsctl
❖ Manages ovs-vswitchd configuration !
❖ ovs-vsctl show!
❖ …!
❖ ovs-vsctl -h

17. ovsdb-tool
❖ Open vSwitch database management utility!
❖ ovsdb-tool create conf.db vswitch.ovsschema!
❖ ovsdb-tool query!
❖ ovsdb-tool -h

19. ovs-ctl
❖ OpenvSwitch Startup Script!
❖ /usr/share/openvswitch/scripts/ovs-ctl!
❖ ovs-ctl start!
❖ ovs-ctl stop!
❖ ovs-ctl -h

20. Match Flow

21. Flow match
OpenFlow Controller
OpenFlow PACKET_IN
ovs-vswitchd
wildcard flow table
datapath flow table
ovs-vswitchd
exactly flow table
unknown packet
upcall (netlink)
Kernel space

22. Flow install
OpenFlow Controller
datapath flow table
ovs-vswitchd
wildcard flow table
ovs-vswitchd
exactly flow table
install flow entry
Kernel space
OpenFlow PACKET_OUT
execute actions
packet out

23. Debugging OpenvSwitch

24. OpenvSwitch Setting

25. Daemon
❖ Start!
❖ ovs-ctl start!
❖ custom init script !
❖ Check!
❖ ovs-ctl status!
❖ ps aux |grep ovs

26. Logging
❖ ovsdb-tool show-log [-mmm]!
❖ cat /var/log/openvswitch/{ovsdb-server,ovs-vswitchd}.
log

27. ovs-vsctl show
❖ Controller!
❖ Connection methods: tcp, ssl!
❖ OpenFlow protocol: 6633, 6653!
❖ is_connected: true!
❖ fail_mode!
❖ secure, standalone

28. ovs-ofctl
OpenFlow Controller
ovs-vswitchd
wildcard flow table
datapath flow table
ovs-vswitchd
exactly flow table
Kernel space

29. ovs-ofctl show <bridge name>
❖ Features Reply!
❖ dpid!
❖ ofport <-> interface

30. ovs-dpctl
ovs-vswitchd
wildcard flow table
datapath flow table
ovs-vswitchd
exactly
OpenFlow Controller
Kernel space

31. ovs-dpctl show
❖ hit!
❖ hit existing entry!
❖ missed!
❖ send to userspace!
❖ drop!
❖ flows

32. Flow

33. ovs-ofctl
OpenFlow Controller
ovs-vswitchd
wildcard flow table
datapath flow table
ovs-vswitchd
exactly flow table
Kernel space

34. ovs-ofctl dump-flows <bridge name>
❖ xid!
❖ check fields!
❖ duration, idle_age, priority, in_port!
❖ actions

35. ovs-dpctl
ovs-vswitchd
wildcard flow table
datapath flow table
ovs-vswitchd
exactly
OpenFlow Controller
Kernel space

36. ovs-dpctl dump-flows
❖ packets!
❖ used!
❖ actions

37. ovs-appctl bridge/dump-flows <br>
❖ Include hidden flow!
❖ Send packet to OpenFlow Controller

38. Thank you