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OpenFlow for Campuses A Tutorial at GEC10 March 15, 2011

OpenFlow for Campuses A Tutorial at GEC10 March 15, 2011. Srini Seetharaman, DT R&D Lab, USA Masa Kobayashi, NEC Labs/Stanford. Introductions. Agenda. Goals of this Tutorial. By the end, everyone should know: what OpenFlow is how it’s used and how you can use it where it’s going

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OpenFlow for Campuses A Tutorial at GEC10 March 15, 2011

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  1. OpenFlow for CampusesA Tutorial at GEC10March 15, 2011 Srini Seetharaman, DT R&D Lab, USA Masa Kobayashi, NEC Labs/Stanford

  2. Introductions

  3. Agenda

  4. Goals of this Tutorial • By the end, everyone should know: • what OpenFlow is • how it’s used and how you can use it • where it’s going • how OpenFlow fits in the Software-Defined Networking (SDN) spectrum • how to slice your network • Present a useful mix of lecture-based content and actual operational info • Have fun

  5. Why OpenFlow?

  6. The Ossified Network Feature Million of linesof source code Billions of gates Routing, management, mobility management, access control, VPNs, … Feature 5400 RFCs Barrier to entry Operating System Specialized Packet Forwarding Hardware Bloated Power Hungry Many complex functions baked into the infrastructure • OSPF, BGP, multicast, differentiated services,Traffic Engineering, NAT, firewalls, MPLS, redundant layers, … • An industry with a “mainframe-mentality”, reluctant to change 6

  7. Research Stagnation • Lots of deployed innovation in other areas • OS: filesystems, schedulers, virtualization • DS: DHTs, CDNs, MapReduce • Compilers: JITs, vectorization • Networks are largely the same as years ago • Ethernet, IP, WiFi • Rate of change of the network seems slower in comparison • Need better tools and abstractions to demonstrate and deploy

  8. Closed Systems (Vendor Hardware) • Stuck with interfaces (CLI, SNMP, etc) • Hard to meaningfully collaborate • Vendors starting to open up, but not usefully • Need a fully open system – a Linux equivalent

  9. Open Systems gap in the tool space none have all the desired attributes!

  10. OpenFlow: a pragmatic compromise • + Speed, scale, fidelity of vendor hardware • + Flexibility and control of software and simulation • Vendors don’t need to expose implementation • Leverages hardware inside most switches today (ACL tables)

  11. How does OpenFlow work? 12

  12. Ethernet Switch

  13. Control Path Control Path (Software) Data Path (Hardware)

  14. OpenFlow Controller OpenFlow Protocol (SSL/TCP) Control Path OpenFlow Data Path (Hardware)

  15. MAC src MAC dst IP Src IP Dst TCP sport TCP dport * * * 5.6.7.8 * * port 1 Action OpenFlow Example Controller PC OpenFlow Client Software Layer Flow Table Hardware Layer port 2 port 1 port 3 port 4 5.6.7.8 1.2.3.4

  16. OpenFlow Basics Flow Table Entries Rule Action Stats Packet + byte counters • Forward packet to zero or more ports • Encapsulate and forward to controller • Send to normal processing pipeline • Modify Fields • Any extensions you add! Eth type Switch Port IP Src IP Dst IP ToS IP Prot L4 sport L4 dport VLAN pcp MAC src MAC dst VLAN ID + mask what fields to match

  17. Switch Port Switch Port Switch Port MAC src MAC src MAC src MAC dst MAC dst MAC dst Eth type Eth type Eth type VLAN ID VLAN ID VLAN ID IP Src IP Src IP Src IP Dst IP Dst IP Dst IP Prot IP Prot IP Prot TCP sport TCP sport TCP sport TCP dport TCP dport TCP dport Action Action Action Examples Switching 00:1f:.. * * * * * * * * * port6 Flow Switching port3 00:20.. 00:1f.. 0800 vlan1 1.2.3.4 5.6.7.8 4 17264 80 port6 Firewall * * * * * * * * * 22 drop

  18. Switch Port Switch Port MAC src MAC src MAC dst MAC dst Eth type Eth type VLAN ID VLAN ID IP Src IP Src IP Dst IP Dst IP Prot IP Prot TCP sport TCP sport TCP dport TCP dport Action Action Examples Routing * * * * * * 5.6.7.8 * * * port6 VLAN Switching port6, port7, port9 vlan1 00:1f.. * * * * * * * *

  19. OpenFlow Switch OpenFlow Switch OpenFlow Switch OpenFlow Switch OpenFlow Switch OpenFlow Switch Centralized vs Distributed ControlBoth models are possible with OpenFlow Centralized Control Distributed Control Controller Controller Controller Controller

  20. Flow Routing vs. AggregationBoth models are possible with OpenFlow Flow-Based • Every flow is individually set up by controller • Exact-match flow entries • Flow table contains one entry per flow • Good for fine grain control, e.g. campus networks • Aggregated • One flow entry covers large groups of flows • Wildcard flow entries • Flow table contains one entry per category of flows • Good for large number of flows, e.g. backbone

  21. Reactive vs. Proactive (pre-populated)Both models are possible with OpenFlow Reactive • First packet of flow triggers controller to insert flow entries • Efficient use of flow table • Every flow incurs small additional flow setup time • If control connection lost, switch has limited utility • Proactive • Controller pre-populates flow table in switch • Zero additional flow setup time • Loss of control connection does not disrupt traffic • Essentially requires aggregated (wildcard) rules

  22. Usage examples Alice’s code: Simple learning switch Per Flow switching Network access control/firewall Static “VLANs” Her own new routing protocol: unicast, multicast, multipath Home network manager Packet processor (in controller) IPvAlice • VM migration • Server Load balancing • Mobility manager • Power management • Network monitoring and visualization • Network debugging • Network slicing … and much more you can create!

  23. Quiz Time • How do I provide control connectivity? Is it really clean slate? • Why aren’t users complaining about time to setup flows over OpenFlow? (Hint: What is the predominant traffic today?) • Considering switch CPU is the major limit, how can one take down an OpenFlow network? • How to perform topology discovery over OpenFlow-enabled switches? • What happens when you have a non-OpenFlow switch inbetween? • What if there are two islands connected to same controller? • How scalable is OpenFlow? How does one scale deployments?

  24. What can you not do with OpenFlow ver1.0 • Non-flow-based (per-packet) networking • ex. Per-packet next-hop selection (in wireless mesh) • yes, this is a fundamental limitation • BUT OpenFlow can provide the plumbing to connect these systems • Use all tables on switch chips • yes, a major limitation (cross-product issue) • BUT an upcoming OF version will expose these

  25. What can you not do with OpenFlow ver1.0 • New forwarding primitives • BUT provides a nice way to integrate them through extensions • New packet formats/field definitions • BUT a generalized OpenFlow (2.0) is on the horizon • Optical Circuits • BUT efforts underway to apply OpenFlow model to circuits • Low-setup-time individual flows • BUT can push down flows proactively to avoid delays

  26. Where it’s going • OF v1.1: Extensions for WAN, spring 2011 • multiple tables: leverage additional tables • tags and tunnels • multipath forwarding • OF v2+ • generalized matching and actions: an “instruction set” for networking

  27. OpenFlow Implementations(Switch and Controller) 28

  28. OpenFlow building blocks Monitoring/debugging tools oftrace oflops openseer Stanford Provided ENVI (GUI) LAVI Expedient Applications n-Casting NOX Beacon SNAC Helios Maestro Controller Slicing Software FlowVisor Console FlowVisor Stanford Provided Commercial Switches Software Ref. Switch NetFPGA Broadcom Ref. Switch HP, NEC, Pronto, Juniper.. and many more OpenFlow Switches OpenVSwitch OpenWRT PCEngine WiFi AP 29

  29. Current SDN hardware Juniper MX-series NEC IP8800 UNIVERGE PF5240 WiMax (NEC) HP Procurve 5400 Netgear 7324 PC Engines Pronto 3240/3290 Ciena Coredirector More coming soon... 30

  30. Commercial Switch Vendors 31

  31. Controller Vendors 32

  32. Growing Community Vendors and start-ups Providers and business-unit More... More... Note: Level of interest varies 33

  33. Software-Defined Networking (SDN) 34

  34. Current Internet Closed to Innovations in the Infrastructure App App App Closed App App App Operating System Specialized Packet Forwarding Hardware Operating System App App App App App App Specialized Packet Forwarding Hardware Operating System Specialized Packet Forwarding Hardware Operating System Specialized Packet Forwarding Hardware App App App Operating System Specialized Packet Forwarding Hardware 35

  35. “Software Defined Networking” approachto open it App App App Network Operating System App App App App App App Operating System Specialized Packet Forwarding Hardware Operating System App App App App App App Specialized Packet Forwarding Hardware Operating System Specialized Packet Forwarding Hardware Operating System Specialized Packet Forwarding Hardware App App App Operating System Specialized Packet Forwarding Hardware 36

  36. The “Software-defined Network” 3. Well-defined open API 2. At least one good operating system Extensible, possibly open-source App App App 1. Open interface to hardware Network Operating System Simple Packet Forwarding Hardware Simple Packet Forwarding Hardware Simple Packet Forwarding Hardware Simple Packet Forwarding Hardware Simple Packet Forwarding Hardware 37

  37. Mininet Setup Controller port6633 c0 loopback (127.0.0.1:6633) OpenFlow Tutorial 3hosts-1switch topology loopback (127.0.0.1:6634) OpenFlow Switch dpctl (user space process) s1 s1-eth0 s1-eth1 s1-eth2 h1-eth0 h3-eth0 h4-eth0 h2 10.0.0.2 h3 10.0.0.3 h4 10.0.0.4 virtual hosts

  38. Switch Configuration Setup Of-demo-6 [eth1] 192.168.40.11 00:1b:21:5d:4e:c5 Of-demo-5 [eth1] 192.168.40.10 00:1b:21:5d:4c:3d GUI 13 A13 A14 14 DisabledBackup hpsw2 15 necsw5 A15 Controller 14 13 Pronto 3290 172.27.75.33 http://www.openflow.org/wk/index.php/OpenFlowTutorialGEC10

  39. Virtualizing OpenFlow 40

  40. Trend App App App App App App Controller 1 Controller 2 Controller 1 Controller 2 NOX (Network OS) Network OS Windows (OS) Linux Mac OS Windows (OS) Linux Mac OS Windows (OS) Linux Mac OS Virtualization or “Slicing” Virtualization layer OpenFlow x86 (Computer) Computer Industry Network Industry

  41. Isolated “slices” Many operating systems, or Many versions App App App App App App App App Network Operating System 1 Network Operating System 2 Network Operating System 3 Network Operating System 4 Open interface to hardware Open interface to hardware Virtualization or “Slicing” Layer Simple Packet Forwarding Hardware Simple Packet Forwarding Hardware Simple Packet Forwarding Hardware Simple Packet Forwarding Hardware Simple Packet Forwarding Hardware

  42. Flow Table Flow Table Controller Controller Switch Based VirtualizationExists for NEC, HP switches but not flexible enough Research VLAN 2 Research VLAN 1 Production VLANs Normal L2/L3 Processing

  43. OpenFlow Switch OpenFlow Switch OpenFlow Switch OpenFlow FlowVisor & Policy Control FlowVisor-based Virtualization Heidi’s Controller Craig’s Controller Aaron’s Controller Topology discovery is per slice OpenFlow Protocol OpenFlow Protocol 44

  44. OpenFlow Switch OpenFlow Switch OpenFlow Switch OpenFlow FlowVisor & Policy Control OpenFlow Protocol FlowVisor-based Virtualization http Load-balancer Multicast Broadcast Separation not only by VLANs, but any L1-L4 pattern dl_dst=FFFFFFFFFFFF tp_src=80, ortp_dst=80 OpenFlow Protocol

  45. FlowSpace: Maps Packets to Slices

  46. Alice Controller Bob Controller Cathy Controller OpenFlow FlowVisor OpenFlow OpenFlow Firmware Data Path FlowVisor Message Handling Rule Policy Check: Is this rule allowed? Policy Check: Who controls this packet? Full Line Rate Forwarding Exception Packet Packet

  47. * * * * * * * * * * * * * * * * * * * * * * * * * * * * 84.65.* 84.65.* Use Case: New CDN - Turbo Coral ++ Basic Idea: Build a CDN where you control the entire network • All traffic to or from Coral IP space controlled by Experimenter • All other traffic controlled by default routing • Topology is entire network • End hosts are automatically added (no opt-in) Switch Port MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport

  48. * * * * * * AaIP !AaIP * * * * * * * * * * * * Use Case: Aaron’s IP • A new layer 3 protocol • Replaces IP • Defined by a new Ether Type Switch Port MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport

  49. OpenFlow/GENI Deployments 50

  50. OpenFlow Deployment at Stanford • Switches (23) • APs (50) • WiMax (1)

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