20+ PSJ Strategywerks Interview Questions and Answers

Explanation of tenant and types, and the consequences of using the same subnet in multiple bridge domains of a single VRF.

• A tenant is a logical entity that groups together a set of networking resources and policies.

• Types of tenants include common tenant, application tenant, and infrastructure tenant.

• Using the same subnet in multiple bridge domains of a single VRF can cause IP address conflicts and communication issues.

• This is because each bridge domain is a separate broadcast...read more

VTEP is a virtual tunnel endpoint and VXLAN is a network overlay technology used for scaling out virtualized data centers.

• VTEP is used to encapsulate and de-encapsulate VXLAN packets.

• VXLAN is used to extend Layer 2 segments over a Layer 3 network.

• VXLAN is used in ACI to provide a scalable and flexible network fabric for multi-tenant environments.

• VXLAN allows for up to 16 million unique network segments.

• VXLAN uses a 24-bit segment ID to identify the virtual network.

• VXLAN packe...read more

Leaf and Spine architecture is used in data center networks for scalability and redundancy. Fabric mode is used for efficient communication between them.

• Leaf and Spine architecture is a two-tier network design where leaf switches connect to spine switches.

• Leaf switches are connected to servers and storage devices while spine switches connect to other switches.

• This architecture provides high bandwidth, low latency, and redundancy.

• Fabric mode is used to create a single logical ...read more

ACI stands for Application Centric Infrastructure. It is a software-defined networking solution by Cisco.

• ACI provides centralized automation and policy-driven application profiles.

• It enables network administrators to manage the entire infrastructure as a single entity.

• ACI supports multi-tenancy, security, and integration with third-party tools.

• It uses a declarative model to define application requirements and automatically configures the network accordingly.

• ACI includes a har...read more

VDC is Virtual Device Context. One supervisor can create up to 4 VDCs.

• VDC allows multiple virtual switches to be created on a single physical switch

• Each VDC has its own set of interfaces, VLANs, routing tables, and management interfaces

• VDCs provide better resource utilization and isolation between different network services

Traffic forwarding between EPGs on the same leaf is achieved through VXLAN encapsulation and routing protocols.

• VXLAN encapsulation is used to create a virtual overlay network that spans multiple physical leaf switches.

• Routing protocols such as OSPF or BGP are used to exchange routing information between the leaf switches.

• The end point user's traffic is encapsulated in a VXLAN packet and forwarded to the destination leaf switch, where it is decapsulated and forwarded to the de...read more

VPC stands for Virtual Private Cloud. It is a virtual network that provides a secure and isolated environment within the public cloud.

• VPC domain is a logical boundary within which resources are created and managed.

• VPC allows multiple virtual machines to communicate with each other as if they were on the same physical network.

• VPC provides high availability and fault tolerance by allowing multiple instances to be deployed across multiple availability zones.

• VPC also allows for t...read more

Bridge domain is a layer 2 construct that separates broadcast domains. VNI is a VXLAN Network Identifier used for overlay networking.

• Bridge domain is used to isolate traffic within a specific VLAN or subnet.

• VNI is a 24-bit identifier used to identify VXLAN segments in an overlay network.

• Both bridge domain and VNI are layer 2 constructs used in network virtualization.

• Bridge domain is not a protocol, but VNI is a protocol used in VXLAN.

• Bridge domain and VNI are commonly used in...read more

ACI provides connectivity to the internet through external Layer 3 networks.

• ACI uses external Layer 3 networks to connect traffic to the internet.

• This is achieved through the use of Border Gateway Protocol (BGP) and External Routing Policies (ERPs).

• ACI also supports the use of Network Address Translation (NAT) to translate internal IP addresses to external IP addresses.

• ACI can be configured to use multiple external Layer 3 networks for redundancy and load balancing.

• ACI also p...read more

IPG refers to Interface Profile Group which is used to group interface profiles. Interface policies define the behavior of interfaces.

• IPG is used to group interface profiles together for easier management.

• Interface policies define the behavior of interfaces such as QoS, security, and VLAN settings.

• IPG can be used to apply interface policies to multiple interfaces at once.

• For example, you can create an IPG for all access ports and apply an interface policy for VLAN settings to...read more

Traffic flow from one leaf endpoint to another leaf endpoint is achieved through spine switches.

• Traffic flows from the endpoint of one leaf switch to the spine switch.

• The spine switch then forwards the traffic to the endpoint of the other leaf switch.

• This is achieved through the use of routing protocols such as OSPF or BGP.

• The spine switches act as intermediaries between the leaf switches.

• This architecture is known as a leaf-spine network topology.

The domain created to connect VMM domains is called the Logical Switch domain.

• Logical Switch domain is created in System Center Virtual Machine Manager (VMM) to connect VMM domains.

• It is used to provide connectivity between virtual machines and physical networks.

• It allows for centralized management of virtual switches and network policies.

• Logical Switch domain can be used to create virtual networks that span multiple hosts and clusters.

• It supports network virtualization and c...read more

ISIS is used in fabric for routing and scalability purposes. Fabric is a network architecture that allows for high-speed, low-latency communication between devices.

• ISIS is a link-state routing protocol that is commonly used in fabric networks.

• Fabric is a network architecture that is designed to provide high-speed, low-latency communication between devices.

• Fabric networks are typically used in data centers and other high-performance computing environments.

• ISIS is used in fabri...read more

Traditional Mac learning is static while conversation Mac learning is dynamic.

• Traditional Mac learning involves manually configuring MAC addresses in the switch's MAC address table.

• Conversation Mac learning involves the switch dynamically learning MAC addresses based on the source address of incoming frames.

• Traditional Mac learning is more prone to errors and requires more manual intervention.

• Conversation Mac learning is more efficient and reduces the risk of errors.

• Conversat...read more

VRF stands for Virtual Routing and Forwarding. It is used in ACI to provide network segmentation and isolation.

• VRF allows multiple virtual networks to coexist on a single physical infrastructure.

• Each VRF has its own routing table, which provides network segmentation and isolation.

• In ACI, VRF is used to create tenant networks and provide policy enforcement between them.

• VRF can also be used to provide secure connectivity between different parts of an organization.

• VRF is commonl...read more

OTV stands for Overlay Transport Virtualization. It is used to extend Layer 2 connectivity between data centers.

• OTV is a Cisco proprietary technology

• It allows for the extension of VLANs across multiple data centers

• It provides a layer of abstraction between the physical network and the logical network

• It helps in reducing the complexity of managing multiple data centers

• It provides a disaster recovery solution by allowing virtual machines to be migrated between data centers

AAEP stands for Application Centric Infrastructure (ACI) Anywhere Endpoint Policy. It is used to enforce endpoint security policies.

• AAEP is a policy that defines how endpoints should be treated in an ACI fabric.

• It is used to enforce security policies for endpoints across different domains.

• AAEP is used to ensure that endpoints are properly classified and that the correct policies are applied to them.

• It is an important component of Cisco's ACI architecture.

• Examples of policies ...read more

Yes, spine-spine connections are possible in a leaf-spine network architecture.

• Spine-spine connections can be used to increase network capacity and redundancy.

• However, it is important to ensure that the spine switches are properly configured to avoid loops.

• Examples of spine-spine connections include MLAG and ECMP.

• Spine-spine connections are commonly used in data center networks.

An orphan port in Nexus is a port that is not associated with any VLAN or interface.

• Orphan ports are also known as unused ports.

• These ports can be used for future expansion or can be disabled to save power.

• Orphan ports can be identified using the 'show interface status' command.

• They can also be configured as Layer 3 ports or assigned to a VLAN.

• Orphan ports can cause security issues if left unsecured.

Bare metal servers are physical servers without any virtualization layer or operating system installed.

• Bare metal servers are also known as dedicated servers.

• They are used for high-performance computing, data-intensive workloads, and applications that require direct access to hardware.

• Bare metal servers can be customized to meet specific requirements.

• Examples of bare metal server providers include IBM, Dell, and HP.

C is a programming language and routing is the process of selecting the best path for network traffic.

• C is a high-level programming language used for system programming and developing applications.

• Routing is the process of selecting the best path for network traffic to reach its destination.

• Routing protocols like OSPF, BGP, and EIGRP are used to determine the best path for network traffic.

• Routing tables are used to store information about network topology and available paths....read more

APIC controllers are used to manage and automate network infrastructure.

• APIC controllers provide a centralized point of control for network infrastructure.

• They automate network provisioning, configuration, and policy management.

• APIC controllers use APIs to communicate with network devices and orchestrate network functions.

• They enable network administrators to easily manage and monitor network traffic and security.

• Examples of APIC controllers include Cisco ACI and VMware NSX-T...read more

What is the difference between routing and switching?

• Routing is the process of finding the best path for data packets to travel from one network to another

• Switching is the process of forwarding data packets between devices on the same network

• Routing is done by routers, while switching is done by switches

• Routing uses IP addresses to determine the best path, while switching uses MAC addresses

• Routing is slower than switching, but is necessary for communication between different ...read more