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• May 24, 2023
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Preparing for a Cisco Network Engineer role? Here’s the guide to Cisco Nexus interview questions to help you ace your interview. Cisco is the industry leader for all things networking. If you are an aspiring Network Engineer or you already work as a Network Engineer and you wish to upskill, the Cisco Nexus technology is the best career move to make.

A Network Engineer implements, maintains, designs, and troubleshoots an organization’s computer networks. Network security and integrity being the major focus of Network Engineers in their daily tasks, it is beneficial for network professionals to learn how to build a network that brings together data centers and cloud computing. 

This is where the knowledge of Cisco Nexus switches comes in handy. In this guide, we have laid down the list of the top 15 most-asked Cisco Nexus interview questions and answers for you to ace your job interview. Whether you’re appearing for a Network Engineer or for a Cisco Nexus interview, it is crucial to have a strong understanding of Nexus concepts.

We have majorly divided the Nexus interview questions into two sections:

• Cisco Nexus interview questions and answers for beginners
• Advanced Cisco Nexus interview questions and answers

Without further ado, let us now begin with the list of Cisco Nexus interview questions!

Cisco Nexus Interview Questions for Beginners:

The following mentioned nexus interview questions are best suited for candidates who are appearing for an entry-level Network Engineer interview. This section explores fundamentals of Cisco Nexus technology. 

01. What is meant by Cisco Nexus?

Cisco Nexus refers to modular switches that are fixed ports and are specially created for data centers. The first introduction of the technology was the Cisco 7000 switches which are a 10-slot chassis. 

Another technology includes Cisco Nexus Operating System (NX-OS) which is a modern data center-class operating system. Therefore, Cisco Nexus is a series of data center switches that are efficient, high-performing, have low latency, and are scalable network solutions. 

Most enterprises use the Nexus switches because they are reliable and flexible.

02. Mention the main features of Cisco Nexus switches.

The Cisco Nexus switches are state-of-the-art switches. They are very different from the normal switches that are used in the industry. The main features include:

• The Cisco Nexus switches have high-density and high-bandwidth switches
• A simplified network device because of a Virtual Port-Channel (vPC) which is a multi-chassis port channel. It increases convergence time as well
• Because of the Fabric Extender technology (FEX), the network is equipped with simplified connectivity
• Advanced security features, including Access Control Lists (ACLs) and TrustSec
• Support for advanced data center protocols such as Fibre Channel over Ethernet (FCoE)
• Modular and scalable architecture
• Deep buffer capabilities for handling small, sudden traffic
• extensive control and monitoring tools provided by Cisco Application Policy Infrastructure Controller (APIC) and Cisco Data Centre Network Manager (DCNM)

03. What sets the Cisco Nexus switch series apart from the other Cisco switch series?

• While other Cisco switch series serve a wider range of networking requirements, the Cisco Nexus series is specifically created for data center environments. 
• For data centers, the Nexus series includes capabilities and protocols like FCoE and virtualization support. 
• Along with that, Nexus switches provide higher port densities, low latency, and advanced features like vPC and FEX, which are essential for modern data centers.

04. What do you understand by Virtual Port Channel (vPC)?

• Virtual Port Channel (vPC) is a technology that allows the creation of a logical link aggregation group (LAG) between two Cisco Nexus switches and a downstream device. 
• It is a multi-chassis port channel with a simplified network design.
• It provides redundancy and load balancing by enabling the downstream device to treat the two Nexus switches as a single logical switch. 
• With vPC, traffic can be distributed across multiple physical links, improving link utilization and providing resiliency in case of link or switch failures.
• It removes the dependency on Spanning Tree Protocol (STP).

05. What are the main components of the vPC?

The important components of the Virtual Port Channel (vPC) are mentioned below:

• vPC Peer-Switch 
• vPC Keep-Alive 
• vPC Domain 
• vPC Peer-Link 
• Member Ports 
• Orphan Ports 

06. What is meant by Fabric Extender (FEX) and what is its purpose?

• Fabric Extender (FEX) is a technology that allows for the extension of fabric to external devices, such as servers or network appliances. 
• FEX provides a simplified approach to connectivity by decoupling the management and data plane, allowing the central management of FEX devices from the parent Cisco Nexus switch. 
• It reduces cable complexity, simplifies management, and enhances scalability in large-scale data center deployments.

07. What is the purpose of the Nexus 7000 series in the data center?

• Modular switches in the Nexus 7000 series are created for the core and aggregation layers of data centers. 
• For big data center deployments, it offers high-density 10 Gigabit Ethernet (GbE) and 40 GbE connections, enabling scalability and performance. 
• The Nexus 7000 series is capable of supporting multi-tenant setups and providing effective data center interconnectivity because of its support for cutting-edge features like MPLS, VDC (Virtual Device Context), OTV (Overlay Transport Virtualization), and FabricPath.

08. What is the difference between Nexus 9000 series and Nexus 7000 series?

The difference between the Nexus 9000 and Nexus 7000 series is given below:

Cisco Nexus Interview Questions for Advanced Professionals:

This section of the guide has all the advanced questions based on Cisco Nexus switches. You will get to dig deeper into the technology and learn more about the types of Nexus switches along with the related technologies.

09. How does Cisco Nexus support data center automation?

• Through programmability and APIs (Application Programming Interfaces), Cisco Nexus switches offer full assistance for data center automation. 
• The network infrastructure may be programmatically configured and managed because of their support for industry-standard protocols including NETCONF, RESTCONF, and OpenConfig. 
• Network managers may automate difficult activities, optimize operations, and maintain uniform standards by integrating Cisco Nexus switches with automation frameworks like Cisco ACI and Ansible.

10. What is Cisco Application Centric Infrastructure (ACI)?

• A software-defined networking (SDN) solution for data center environments is Cisco Application Centric Infrastructure (ACI). 
• ACI is a policy-driven architecture that automates network provisioning and management while removing network infrastructure. 
• It allows administrators to create policies depending on the demands of the applications, simplifying network deployment and reducing human error in manual configuration. 
• In order to provide application-aware network policies and easy application deployment across multi-vendor setups, ACI brings together teams from the network, security, and application domains.

11. How does Cisco Nexus provide high availability and fault tolerance?

Cisco Nexus switches put together several features to ensure high availability and fault tolerance in data center networks. Some of these features include:

• Virtual Port Channel (vPC) for link redundancy and load balancing
• Hot-swappable power supplies and fans for non-stop operation
• In-service software upgrades for minimizing downtime during upgrades
• Graceful restart and non-stop forwarding for faster convergence
• Equal-Cost Multipath (ECMP) for load balancing and redundancy at the network layer
• Spanning Tree Protocol (STP) enhancements such as Bridge Assurance and Rapid PVST+ for loop prevention and fast convergence
• FabricPath or VXLAN-based overlays for scalable and resilient Layer 2 connectivity

12. Mention all the different types of Nexus switches available.

The various types of Cisco Nexus switches are mentioned as follows:

• Cisco MDS 9000 SAN switches:

The data center Storage Area Network (SAN) infrastructure is supported by these switches.

• Nexus 1000V series switches:

It is present inside the VMware ESX hypervisor and uses Cisco Nexus Operation System (NX-OS) software. Not to forget that this switch is a software-based switch.

• Nexus 2000 series switches:

It uses FEX technology to give flexible data center deployment models to fulfill the demand for servers.

• Nexus 3000 series switches:

In the case of general-purpose deployments, the 3000 series switches provide Layer 2 and Layer 3 switching and cloud networks.

• Nexus 5000 series switches:

These switches are the high-density layer 2 and 3 switches with 10/40G ethernet port facilities. These can support a large number of source ports, VLANs and VSANs.

• Nexus 7000 series switches:

These switches provide data center architecture on one platform that includes data center core, aggregation and access layer. These switches provide high-density 10G, 40G and 100 GB Ethernet along with bandwidth per slot up to 1.3Tbps.

• Nexus 9000 series switches:

These switches can run Nexus Operating System (NX-0S) and Application Centric Infrastructure (ACI) modes. It consists of both modular as well as fixed switches. Additionally, these also provide 1G, 10G, 40G and 100 GB Ethernet (GE) configurations.

13. What is meant by DCNM?

• Expanded as Data Center Network Manager, the Cisco DCNM is a central management dashboard for data center fabrics that are based on Cisco Nexus switches, MDS and Cisco UCS.
• The main benefit of DCNM is that they reduce operation costs by providing efficient operations, monitoring, and troubleshooting Data Center network infrastructure.
• A Network Engineer can manage switches and automate Restful APIs through its graphical interface.

14. How is Data Center Interconnect (DCI) supported by Cisco Nexus?

Cisco Nexus switches offer various features and technologies to support Data Center Interconnect (DCI), enabling easy integration and communication between multiple data centers. Some of the key technologies include:

• Overlay Transport Virtualization (OTV): 

OTV allows the extension of Layer 2 connectivity across data centers, enabling VM mobility and disaster recovery capabilities.

• Virtual Extensible LAN (VXLAN): 

VXLAN is an encapsulation technique that extends Layer 2 networks over Layer 3 networks, providing scalability and flexibility for multi-tenant environments and enabling workload mobility between data centers.

• Data Center Interconnect using MPLS (DCI-MPLS): 

Cisco Nexus switches support MPLS-based DCI, allowing the creation of MPLS-based VPNs between data centers. This enables secure and scalable connectivity between data centers that are present in different regions.

• FabricPath:

FabricPath is a fast and reliable Layer 2 routing protocol, and Cisco Nexus switches support it. A multipath, loop-free Ethernet network can be built using FabricPath, increasing scalability and simplifying management.

• Virtual PortChannel (vPC): 

vPC allows the creation of a logical link aggregation group (LAG) between two Nexus switches, increasing bandwidth, providing redundancy, and balancing load for DCI deployments.

• Multiprotocol Border Gateway Protocol (MP-BGP):

Cisco Nexus switches support the Multiprotocol Border Gateway Protocol (MP-BGP), which is used to exchange routing data between data centers. MP-BGP enables effective connectivity and routing between various IP subnets in various data centers.

15. Can Cisco Nexus switches be used in a multi-vendor network?

Cisco Nexus switches can be used in a multi-vendor network as well. Yet, it is crucial to make sure that proper integration is carried out with other vendors’ equipment for the smooth functioning of the network. Network experts can help carry out the smooth operation of Cisco Nexus switches with other equipment to reduce any potential problems.

Conclusion

In this Cisco Nexus interview questions and answers guide, we have laid down the questions for the most important technologies involved and related to Cisco Nexus switches. We covered the types of Nexus switches available, and we covered important concepts like Virtual Port Channel (vPC), Fabric Extender (FEX), Data Center Interconnect (DCI), Data Center Network Manager (DCNM), and much more.

We also learn the difference between the various switches, especially the Nexus 7000 series and Nexus 9000 series. This guide makes you familiar with the Cisco Nexus technology. After reading these nexus interview questions, you can confidently approach a Cisco Nexus interview and showcase your knowledge in this crucial area of networking.