Datacenter Design VI ( SDN )

Software Defined Networking

• Advantages SDN
  • Automatic Infrastructure Provisioning
  • Multi-tenant enviornments
  • Flexible Placement of servers ( Mobility )
  • Health monitoring of applications
  • Application to NET ( Southbound ) and NET to application ( Northbound ) communication
• Cisco’s SDN implementation: Application Centric Infrastructure ( ACI )

Three key ingredients for ACI

• Nexus 9000 series / 9300 / 9500.
• Aplication Policy Infrastructure Controller ( APIC ).
  • Cisco recommends a minimum of three APIC servers.
• Policy Model ( “What talks to what and how” ).

How it works

• SDN Fabric is build by all the devices.
• APIC are on the Underlay Network.
• All connections are routed ( ECMP ) All links can be utilized.
• ACI creates an Overlay Network.
  • VXLAN  – Virtual Extensible LAN.
  • NVGRE – Network Virtualization using Generic Routing Encapsulation.
    • Both VXLAN and NVGRE add an outside header to identify the Overlay Network.
    • 24-bit header (16000 IDs).
• https://en.wikipedia.org/wiki/Virtual_Extensible_LAN
• https://en.wikipedia.org/wiki/Network_Virtualization_using_Generic_Routing_Encapsulation

Reality of SDN

• New, minimizes data center capital Investment
• Cisco ACI, Vmware NSX platforms locked to vendor
  • Opendaylight example of Vandor inspecific Solutions
• Private cloud orchestration platform needed (ties everything together )