Tag Archives: virtualization

Cisco Nexus Functional Planes

Cisco Nexus

One of the key Cisco Nexus switch features to ensure great availability and high performance is the separation of traffic and processing of traffic into what are called different planes. The three main planes are:

  • Data
  • Control
  • Management

Data refers to packets that are being transferred between systems – for example, the packets that make up a website that a client is accessing. Control traffic is that traffic that helps make the infrastructure functional and intelligent. For example, Spanning Tree Protocol traffic at Layer 2 and OSPF traffic at Layer 3. Finally, management traffic might consist of SSH access and SNMP packets.

Notice the illustration above – it shows different traffic forms flowing through the device. From the bottom up – these traffic flows shown are data, services, control, and management traffic. Notice how interface Access Control Lists can restrict all of these traffic forms on ingress. Control Plane Policing (CoPP) permits the limiting of control, services, and management traffic to ensure the CPU does not experience a Denial of Service (malicious or otherwise) during network activity.

Notice also from the graphic the intentional separation of the control plane traffic and the data traffic. By design, the data traffic is switched through the system while bypassing the control plane. This adds stability and performance to the system.

Something else to consider in the Nexus architecture is the ability for failed services to restart and (hopefully) not affect forwarding on the device. A System Manager watches over the processes running on the system and can restart them in a stateful manner (thanks to a setting called the HA Policy). The process can restart with state information thanks to a Persistent Storage Service that the System Manager can access for the previous state information for the process.

This post represents a high-level overview of this subject covered in detail in the 200-155 course at CBT Nuggets releasing in June of 2018.

Trending in Tech for 2014

I read a great article in the Investors Business Daily speaking to the tech trends of 2014. I wanted to share the main points with my blog readers.


Trend 1 – spending shifting to the cloud. Companies will be investing more heavily in things like Amazon Web Services at the cost to more traditional hardware and service companies such as HP, Oracle, and IBM. Pricing battles will heat up for cloud services as companies like Google and Microsoft try and compete more aggressively with Amazon.

Trend 2 – a big year for tech IPOs. Mobile, social, cloud, and big data companies will follow the success of IPOs in 2013.

Trend 3 – the Internet of Things. Companies like Cisco, Intel, and Qualcomm will ramp up their push and support on the Internet of Things. This trend is about what my blog readers have known for a long time – that more and more devices will feature Internet connectivity. I think we will surely see more and more IPv6 in this area of course.

Trend 4 – software-defined anything. More and more, software is defining the way in which networking functions. The hardware is more and more dominated by software that virtualizes everything.

Trend 5 – old guard tech fights on. Long dominant tech giants like IBM, Cisco, Microsoft, and Oracle are continuing to struggle to adapt to cloud computing and software as a service. The giants will try and move fast enough to keep up with these sweeping changes.

Thanks for reading and I look forward to enjoying this amazing journey with you in 2014!