Ch 02 --- sdn and openflow architecture
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This document provides an overview of SDN and OpenFlow. It describes the traditional network structure with separate control, forwarding, and management planes. With SDN, the control plane is centralized into a controller that programs "dumb" switches via the OpenFlow protocol. The controller manages flow tables on switches to determine how traffic is forwarded. Key OpenFlow components include the controller, OpenFlow channel, flow tables, group tables, and meter tables. The document provides examples of how OpenFlow can implement switching, routing, firewalls, and other network functions through flow table entries.
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Ch 02 --- sdn and openflow architecture
- 1. NDI Communications - Engineering & Training SDN & NFV Chapter 2 – SDN and OpenFlow
- 2. Page 2 Chapter Content Network architecture Network components Tables Applications 2
- 3. Page 3 Traditional Network Structure C C C C Forwarding Plane: End to end packets forwarding Control Plane: Track topology changes, calculating routes, QoS and security considerations and more M M M M Management Plane: Measurements and configuration
- 4. Page 4 Software Defined Networking (SDN) OpenFlow Logically centralized control Smart, Slow controller Dumb, Fast switches Controller M Business Applications
- 5. Page 5 Chapter Content Network architecture Network components Tables Applications
- 6. Page 6 Traditional Switch Forwarding L2/VLANs Table L3 Table ACLs, QoS Security, LB Packets in Packets out
- 7. Page 7 Open Flow Switch Forwarding Flow table Packets in Packets out Flow table Flow table Flow table SDN Controller
- 8. Page 8 Open Flow Components Controller OpenFlow Channel Flow Table Flow Table Flow Table Open Flow Protocol Group Table Tables pipeline Meter Table
- 9. Page 9 The Flow Table – Principle of Operation Flow entry Flow entry Flow entry Flow entry Controller Open Flow Protocol Flow Table Match Condition Instructions…. ….
- 10. Page 10 OpenFlow Switch Operations Controller OpenFlow Channel Flow Table Flow Table Flow Table Open Flow Protocol Group Table Tables pipeline Packet In Packet Out Meter Table
- 11. Page 11 OpenFlow Controller Manages one or more switches via OpenFlow channels Uses OpenFlow protocol to communicate with a OpenFlow aware switch. Provides a network wide abstraction for the applications on north bound. Responsible for programming various tables in the OpenFlow Switch. OpenFlow Switch Controller OpenFlow Switch OpenFlow Switch App. App. OpenFlow Protocol Abstraction layer
- 12. Page 12 OpenFlow Controller - Redundancy Single switch can be managed by more than one controller for load balancing or redundancy purpose. In the case of more than one controller, the controller can take any one of the following roles: Master Slave Equal OpenFlow Switch Controller OpenFlow Switch OpenFlow Switch Controller App. App. OpenFlow Protocol Abstraction layer
- 13. Page 13 Controller's Architecture Single Equal Level Master-Slave
- 14. Page 14 OpenFlow Channel Used to exchange OpenFlow message between switch and controller. Switch can establish single or multiple connections to same or different controllers (auxiliary connections). A controller configures and manages the switch, receives events from the switch, and send packets out the switch via this interface OpenFlow Switch Controller Controller OpenFlow Protocol
- 15. Page 15 OpenFlow Switch Consists of one or more flow tables, group table and meter table. A single switch can be managed by one or more controllers. The flow tables and group table are used during the lookup or forwarding phase in order to forward the packet to appropriate port. Meter table is used to perform simple QOS operations like rate-limiting to complex QOS operations like DiffServ OpenFlow Channel Flow Table Flow Table Flow Table Group Table Packet In Packet Out Meter Table
- 16. Page 16 OpenFlow Physical & Logical Ports Packets In/Out Packets In/Out OpenFlow Switch Logical Port Physical Port The OpenFlow physical ports are switch defined ports that correspond to a hardware interface of the switch. The OpenFlow logical ports are switch defined ports that don’t correspond directly to a hardware interface of the switch.
- 17. Page 17 OpenFlow Reserved Ports OpenFlow reserved ports specify generic forwarding actions such as sending to the controller, flooding, or forwarding using non- OpenFlow methods, such as “normal” switch processing. There are required and optional reserved ports: Required: ALL, CONTROLLER, TABLE, IN PORT, ANY Optional: LOCAL, NORMAL, FLOOD
- 18. Page 18 OpenFlow Required Reserved Ports Packets In/Out Packets In/Out OpenFlow Switch Controller IN PORT: Represents the packet ingress port. ANY: Special value used in some OpenFlow requests when no port is specified ALL: Represents all ports the switch can use for forwarding a specific packet. CONTROLLER: Represents the control channel with the OpenFlow controllers TABLE: Represents the start of the OpenFlow pipeline.
- 19. Page 19 OpenFlow Optional Reserved Ports Packets In/Out Packets In/Out OpenFlow Switch ControllerLOCAL: Represents the switch’s local networking stack and its management stack. NORMAL: Represents forwarding using the traditional non-OpenFlow pipeline of the switch. FLOOD: Represents flooding using the traditional non- OpenFlow pipeline of the switch.
- 20. Page 20 Chapter Content Network architecture Network components Tables Applications
- 21. Page 21 Table Types There are 3 types of tables in the OpenFlow switch: Flow table – the standard table that allows to forward packet to a single port Group table – used for special actions like multicast, broadcast, load balancing and others Meter table – uses Per-flow meters that enables OpenFlow to implement various QoS operations OpenFlow Channel Flow Table Flow Table Flow Table Group Table Packet In Packet Out Meter Table
- 22. Page 22 Flow Tables Structure Match Instructions Modify Field Remove from queue Forward NORMAL FLOOD Virtual Port Physical Port Forward Mandatory Instructions: • Forward packet to port(s) • Encapsulate and forward to controller • Drop packet • Send to normal processing pipeline • Modify Fields Mandatory Instructions: • Forward packet to port(s) • Encapsulate and forward to controller • Drop packet • Send to normal processing pipeline • Modify Fields Optional InstructionsOptional Instructions Timeout Match Instructions Timeout Match Instructions Timeout Match Instructions Timeout … Ingress Port Ethernet SA DA Type IP SA DA Proto TCP/UDP Src VLAN ID Priority TOS Dst Virtual Port ALL CONTROLLER LOCAL TABLE IN_PORT Drop Priority Priority Priority Priority Counters Counters Counters Counters Cookie Cookie Cookie Cookie Flags Flags Flags Flags
- 23. Page 23 Instructions Meter meter_id (optional): Direct packet to the specified meter. Apply-Actions action(s) (Optional): Applies the specific action(s) immediately, without any change to the Action Set. Clear-Actions (Optional): Clears all the actions in the action set immediately. Write-Actions action(s) (Required): Merges the specified set of action(s) into the current action set Goto-Table next-table-id (Required): Indicates the next table in the processing pipeline.
- 24. Page 24 Action Set 1. copy TTL inwards: apply copy TTL inward actions to the packet 2. pop: apply all tag pop actions to the packet 3. push-MPLS: apply MPLS tag push action to the packet 4. push-PBB: apply PBB tag push action to the packet 5. push-VLAN: apply VLAN tag push action to the packet 6. copy TTL outwards: apply copy TTL outwards action to the packet 7. decrement TTL: apply decrement TTL action to the packet 8. set: apply all set-field actions to the packet 9. qos: apply all QoS actions, such as set queue to the packet 10.group: if a group action is specified, apply the actions of the relevant group bucket(s) in the order specified by this list 11.output: if no group action is specified, forward the packet on the port specified by the output action
- 26. Page 26 Table Match Packet in (Start in table 0) Match in table N? Update counters Execute instructions YES Table-miss entry exist? Drop Packet Goto next entry in table N NO NO YES Execute action set NO YES
- 28. Page 28 Data Plane – SDN Switch (Example) Simple packet-handling rules Pattern: match packet header bits Actions: drop, forward, modify, send to controller Priority: disambiguate overlapping patterns Counters: #bytes and #packets 1. src=10.20.*.*, dest=31.22.5.* drop 2. src = *.*.*.*, dest=3.4.*.* forward(2) 3. src=192.1.2.3, dest=*.*.*.* send to controller
- 29. Page 29 Examples (1) Switching * Switch Port MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport Action * 00:1f:.. * * * * * * * port6 Flow Switching port3 Switch Port MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport Action 00:20.. 00:1f..0800 vlan1 1.2.3.4 5.6.7.8 4 17264 80 port6 Firewall * Switch Port MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport Action * * * * * * * * 22 drop
- 30. Page 30 Examples (2) Routing * Switch Port MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport Action * * * * * 5.6.7.8 * * * port6 VLAN Switching * Switch Port MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport Action * * vlan1 * * * * * port6, port7, port9 00:1f..
- 31. Page 31 Group Table A group table consists of group entries. The ability for a flow entry to point to a group enables OpenFlow to represent additional methods of forwarding (e.g. select and all) Group Identifier Action bucketsGroup type Counters
- 33. Page 33 Meter Table A meter table consists of meter entries, defining per-flow meters. Per-flow meters enable OpenFlow to implement various simple QoS operations, such as rate-limiting, and can be combined with per-port queues to implement complex QoS frameworks, such as DiffServ. Meter Identifier Meter Bands Counters Band type Rate Burst Counters Type specific arguments
- 35. Page 35 Chapter Content Network architecture Network components Tables Applications
- 36. Page 36 Unifies Different Kinds of Boxes Router Match: longest destination IP prefix Action: forward out a link Switch Match: destination MAC address Action: forward or flood Firewall (Packet filtering) Match: IP addresses and TCP/UDP port numbers Action: permit or deny NAT Match: IP address and port Action: rewrite address and port 36
- 37. Page 37 Example OpenFlow Applications Dynamic access control Seamless mobility/migration Server load balancing Network virtualization Using multiple wireless access points Energy-efficient networking Adaptive traffic monitoring Denial-of-Service attack detection
- 38. Page 38 OpenFlow in the Wild Open Networking Foundation Google, Facebook, Microsoft, Yahoo, Verizon, Deutsche Telekom, and many other companies Commercial OpenFlow switches HP, NEC, Quanta, Dell, IBM, Juniper, … Network operating systems NOX, Beacon, Floodlight, Nettle, ONIX, POX, Frenetic Network deployments Eight campuses, and two research backbone networks Commercial deployments (e.g., Google backbone)
- 39. Page 39 Summary Yoram Orzach yoram@ndi-com.com Thank You!!! Coming soon LIVE on our NEW e-Learning portal