Goto-table action

Definition

A goto-table action is a fundamental mechanism in the OpenFlow protocol that directs packets to a specific flow table based on the matching criteria defined in the flow entries. This action allows for greater flexibility and control in network traffic management, enabling more complex decision-making by the controller as it processes packets. By using goto-table actions, network devices can efficiently handle different types of traffic and apply different processing rules without needing to revert back to the controller for every packet.

5 Must Know Facts For Your Next Test

1. Goto-table actions were introduced in OpenFlow version 1.3, allowing for a more modular approach to packet processing by enabling packet forwarding to specific tables.
2. This action supports a hierarchical structure of flow tables, where each table can have its own set of flow entries, improving scalability and manageability.
3. Goto-table actions help reduce the need for constant communication between switches and the controller, minimizing latency and improving overall network performance.
4. By directing packets to different flow tables, goto-table actions enable more sophisticated traffic engineering and policy enforcement within networks.
5. In scenarios where specific flows require different treatment, goto-table actions allow for dynamic adjustments based on real-time conditions without affecting the entire network.

Review Questions

• How does the goto-table action enhance packet processing efficiency in OpenFlow?
  • The goto-table action enhances packet processing efficiency by allowing switches to route packets directly to designated flow tables based on predefined criteria. This reduces the number of times packets need to go back to the controller for decisions, resulting in lower latency and improved speed. It also enables more complex routing scenarios by allowing different flow tables to handle various types of traffic, thus streamlining the overall packet handling process.
• In what ways do goto-table actions contribute to the modular design of flow tables in OpenFlow?
  • Goto-table actions contribute to the modular design of flow tables by enabling a hierarchical arrangement where each table can be independently managed with its own set of flow entries. This allows for greater flexibility in defining how packets are processed at various stages in the network. As different types of traffic are directed to specific tables, it facilitates specialized handling for each type, enhancing both performance and manageability within the network architecture.
• Evaluate the impact of goto-table actions on network policy enforcement and traffic management in SDN environments.
  • Goto-table actions significantly impact network policy enforcement and traffic management by providing granular control over how packets are handled at various points in a network. This capability allows operators to implement complex policies that can adapt in real-time based on network conditions. The ability to direct packets through different tables means that network administrators can enforce quality of service (QoS), prioritize critical applications, and respond quickly to changing traffic patterns without overwhelming the controller or disrupting overall performance.

Related terms

Flow Table:

A data structure in OpenFlow switches that stores flow entries, each specifying actions to take for matching packets.

Match Fields: Criteria defined in a flow entry used to determine if a packet matches that entry, which can include parameters like source and destination IP addresses.

OpenFlow Protocol:

A standard communication protocol used in Software-Defined Networking (SDN) to enable the separation of the control plane from the data plane in network devices.