Software Defined Networking

Im SDN wird die Control Plane von der Hardware gelöst und abstrahiert
Innerhalb der Application Layer sitzt die Business Anwendung die dann dem Control Layer sagt was für die Anwendung benötigt wird
Änderungen in der Network Device Architektur
Die klassische Control Plane wird aus dem Gerät herausgenommen und zentralisiert
Vergleichbar mit einem WLC
Hybrid SDNs ist der Großteil der Control Layer ausgelagert, Geräte behalten aber teilweise gewisse Logik

APIs

Durch die APIs können die Layer miteinander sprechen
Üblicherweise werden CRUD Operationen durchgeführt
- Create, Read, Update, Delete

Newer method of network access; Old approach was to assign each interface a static VLAN
Within SD Access the traffic flow is now based on the user identity
- Not depended anymore on physical location or IP address
Requirement: Cisco ISE
Using of an underlay, overlay and fabric network
- Underlay Network: The underlay network describes the physical typology of the connected devices. It means how the devices are physically connected.
- Overlay Network: logical typology; usage of VXLAN to create tunnels on the data plane; usage of LISP on the control plane to build best path for VXLAN; usage of TrustSec policies on the policy plane (ISE requiered)
- Fabric: Describes the whole underlay and overlay network
Usage of Edge Nodes on site of end devices/ hosts
Usage of Control Plane Nodes for central control plane

DNA = Digital Network Architecture
Controller for SD-Access
Based on the idea of intend based networking
- Configuration based on the intend, not the outcome
- maybe comparable to IaC?
Capable of Zero Trust Provisioning through DNS or DHCP entry
Example:
- QoS Implementation
  - Old way: Configure QoS on all systems manually.
  - New way: Define a policy on Cisco Catalyst Center; Catalyst Center will deploy configuration on all devices based on that policy.