Chapter 45 - Introduction to Controller-Based Networking Flashcards
1
Q
What is the Data Plane of a network?
A
- The tasks that a network device completes to forward a message. Regardless of whether it is Layer 2, or 3.
- Handled by an ASIC more often than the CPU
- Also known as the Forwarding Plane
- Examples of tasks completed at the Data Plane are:
- Encapsulating and deencapsulating a packet in a frame
- Adding or removing an 802.1Q header
- Matching a MAC to its entry in a MAC Address Table
- Matching an IP to its entry in a Routing Table
- Encrypting data and adding a new IP header for VPN
- Changing source or destination address for NAT
- Discaring a message due to a filter for ACLs or port security
2
Q
What is the Control Plane of a network?
A
- Provides data to the Data Plane so that it can perform its tasks. Performs overhead work.
- Handled by the CPU
- Controls the Data Plane
- Examples of data sourced by the Control Plane is:
- Routing Protocols
- IPv4 ARP
- IPv6 NDP
- Switch MAC Learning
- STP
3
Q
What is the Management Plane of a network?
A
- Contains protocols that allow engineers to manage hardware. Performs overhead work.
- Handled by the CPU
- Examples of Management Plane protocols are:
- Telnet
- SSH
- SNMP
- Syslog
4
Q
What is SDN?
A
- Software Defined Networking
- Also known as Software Defined Architecture or Controller Based Networking
- Uses a Centralised Control Plane via an SDN Controller. Although some SDNs centralise the control plane more than others.
- Interacts with networking devices via APIs
5
Q
What is a Distributed Control Plane?
A
- This is when the control plane of a network is distributed between multiple devices rather than being centralised to a Controller
- For example, multiple routers connected running OSPF will communicate routes with each other
- Used in traditional networks
6
Q
What is a Centralised Control Plane?
A
- A control plane that has all of its control plane data stored and processed by a single device. A controller.
7
Q
What are examples of SBIs?
A
- OpenFlow
- OpFlex - Uses a declarative SDN model
- Telnet/SSH and SNMP used with Cisco APIC-EM (Controller)
- Telnet/SSH, SNMP, and NETCONF used with Cisco Software Defined Access (Controller)
- OnePK - Cisco proprietary
8
Q
What is a Southbound Interface?
A
- SBI for short
- The virtual interface on a Controller that connects to the networking devices it controls
- Often utilises an API to allow the Controller to communicate with networking devices and program the Control Planes of each networking device with data that is used by the Data Plane
9
Q
What is an API?
A
- Application Programming Interface
- A way of allowing one application to exchange data with another
10
Q
What information would a Controller gather about its network?
A
- A list of all devices in the network
- The capabilities of each device
- The interfaces on each device
- The current state of each interface
- The topology (which devices connect to which via which interfaces)
- Device configuration (IP Addresses, VLANs)
11
Q
What is a Northbound Interface?
A
- NBI for short
- The virtual interface on a Controller that allows its data and functions to be used by other programs. Also what allows engineers access to the controller.
- Often uses an API to allow the Controller to communicate with applications. The applications are sometimes located on the same machine, sometimes elsewhere in the network. In this situation a REST API is required.
12
Q
What is a REST API?
A
- Representational State Transfer Application Programming Interface
- Utilised in instances where the Controller is not located on the same system as an application that wants to access it.
- Allows HTTP messages to be sent between Controller and application over the network
- Not an API itsself but defines how an API should work
13
Q
What are the common formats used for network programming?
A
- JSON (JavaScript Object Notation)
- XML (eXtensible Markup Language)
14
Q
List SDN solutions
A
- OpenDaylight Controller
- Cisco Application Centric Infrastructure (ACI)
- Cisco APIC Enterprise Module (APIC-EM)
15
Q
What is the ONF?
A
- Open Networking Foundation
- A community of users and vendors that aim to establish SDN in the market
- Developed the OpenFlow model SDN which defines the protocols and standards that SDNs use. For example it defines the concept of a controller and the standards a switch needs to follow in order to support OpenFlow (Switch Abstraction)
