Virtualization Functions (NFVI, VNF)

This topic is to discuss the following lesson:

what is the use of nexus switches in NFVI ? is it to connect to external network or NFV fucntion can virtualize nexus switch function ? does it replace existing router switches or does it use existing hardware routers and switches for Network virtualization. - confusing on NFV concept.
Appreciate if anyone can give some light on it.


Hello Umesh

The NFVI as a framework has several components. These components can be separated into two categories: hardware and virtual. Among the hardware components are the Nexus series devices. Nexus devices essentially provide the physical connection to the virtualized NFVI environment. Looking at the diagram below, the nexus switches would fall under the “Hardware Network” component at the bottom right.

This might sound philosophical, but I believe it will clarify some things. We live in a physical world, and the interfaces we require are physical So even if you virtualize a large part of servers and networks, you still need some interface to the physical world to connect those portions of the network that are indeed physical. That’s where the nexus switches come in. They are the physical interface to the NFVI environment.

Only nexus devices support the Cisco NFV infrastructure and that’s why the are mentioned here. You can find out more about it at the following Cisco link:

I hope this has been helpful!


Hello Laz,
Thanks for clarification.

1 Like

Hi Rene,

I’d like to know what Cisco are meaning by “L4/L6” in the official Cisco blueprint of CCIEs Evolving Technologies v1.1 exam topic specially the topic that this lesson is what about which is “6.1.b [iii] Virtualization functions (NFVi, VNF, and L4/L6)” ?

Best Regards,