Tag Archives: data

CCIE Evolving Technologies – YANG


OK, this has to be one of the greatest names in technology – it is YANG (Yet Another Next Generation modeling language). YANG is a powerful data definition language.

As you know, Simple Network Management Protocol (SNMP) has improved over the years and has been a key ingredient for effective network management. While there have been massive improvements in areas like security, SNMP tends to be implemented for monitoring much more than it is used for the actual configuration of devices.

YANG offers an alternative to SNMP when it comes to network device configuration. YANG is defined in RFC 6020. As a data modeling approach, YANG describes:

  • Whatever can be configured on a device
  • Everything that can be monitored on a device
  • All administrative actions that can be accomplished on a device
  • All the notifications possible on a network device

The YANG model uses a tree structure. This is a very common approach with data modeling. YANG follows a structure that is similar to XML, and YANG is built in modules.

Here is an example of YANG in action:

list interface {
      key “name”;

      leaf name {
             type string;
      leaf speed {
             type enumeration {

                      enum 10m;
                      enum 100m;
                      enum auto;
       leaf observed-speed {
               type uint32;
               config false;

Notice how the interface speed can be configured with three potential values, while the observed speed is not configurable.

This post is a summary of the excellent content found in the recently released CCIE and CCDE Evolving Technologies Study Guide from Cisco Press. This information is also demonstrated in my soon to be released CBT Nugget Evolving Technologies course.

CCNA Data Center DCICT (200-155) CBT Nuggets Outline


By popular demand – here is the rough outline of the exciting new CCNA Data Center course I am working on at CBT Nuggets!

  1. Introduction: The CCNA Data Center
  2. Introduction: Getting Your Hands on Equipment
  3. Network Virtualization: Module Introduction
  4. Network Virtualization: Functional Planes
  5. Network Virtualization: Default and Management VRFs
  6. Network Virtualization: OTV
  7. Network Virtualization: NVGRE
  8. Network Virtualization: VXLAN
  9. Network Virtualization: Troubleshooting VDC STP
  10. Networking Technologies: Module Introduction
  11. Networking Technologies: Configuring FEX
  12. Networking Technologies: Configuring vPC
  13. Networking Technologies: Configuring FabricPath
  14. Networking Technologies: Configuring Unified Switch Ports
  15. Networking Technologies: Benefits of the Unified Fabric
  16. Networking Technologies: RBAC
  17. Unified Computing: Module Introduction
  18. Unified Computing: Server Types
  19. Unified Computing: Connectivity
  20. Unified Computing: Cisco UCS
  21. Unified Computing: Hardware Abstraction
  22. Unified Computing: Configuring High Availability
  23. Unified Computing: Configuring Port Roles
  24. Unified Computing: Configuring Hardware Discovery
  25. Unified Computing: Hypervisors
  26. Unified Computing: Virtual Switches
  27. Unified Computing: Shared Storage
  28. Unified Computing: VM Components
  29. Unified Computing: Virtual Machine Manager
  30. Automation and Orchestration: Module Introduction
  31. Automation and Orchestration: Using APIs
  32. Automation and Orchestration: Cloud Computing
  33. Automation and Orchestration: UCS Director
  34. Automation and Orchestration: Troubleshooting a UCS Director Workflow
  35. Application Centric Infrastructure: Module Introduction
  36. Application Centric Infrastructure: The ACI Environment
  37. Application Centric Infrastructure: ACI Fabric Discovery
  38. Application Centric Infrastructure: The ACI Deployment Model
  39. Application Centric Infrastructure: The ACI Logical Model