BT Group Network Engineer Interview Questions, Process, and Tips

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 automatic...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.

• Examp...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 ...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 hig...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-...read more

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 lea...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

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 Lay...read more

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 c...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 acces...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 protoco...read more

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.

• ...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...read more

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.

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 h...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.

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 deploye...read more

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.

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...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 ...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