Network Functions, Components and Services

What is the purpose of network functions and components in cloud architecture?

They connect, protect, direct, and manage network traffic.

What does a load balancer do?

It distributes incoming traffic across multiple servers to prevent overload.

Why is load balancing important in cloud environments?

It improves availability, performance, and scalability.

What is an application load balancer (ALB)?

It distributes traffic based on application-level information, such as HTTP requests and URLs.

How does an ALB decide where to send traffic?

It examines application-layer details, such as the requested path or host.

When would you use an ALB?

When traffic needs routing based on website paths or application content.

What is a network load balancer (NLB)?

It distributes network traffic using connection information, such as IP addresses and ports.

How does an NLB differ from an ALB?

An NLB operates at the network or transport level; an ALB uses application-level information.

When would you use an NLB?

When handling high volumes of traffic that require low latency.

What is an application gateway?

It manages and routes application traffic between clients and backend services.

How can an application gateway improve application security?

It can inspect application traffic and apply rules before forwarding requests.

What is a content delivery network (CDN)?

A distributed network of servers that delivers content from locations closer to users.

How does a CDN improve website performance?

It caches content near users, reducing latency and loading time.

What type of content is commonly delivered through a CDN?

Images, videos, web pages, and other static content.

What is a firewall?

A security system that allows or blocks network traffic based on rules.

How does a firewall protect cloud resources?

It filters traffic to prevent unauthorized network access.

What is a virtual private cloud (VPC)?

A logically isolated network environment within a cloud provider.

Why would an organization create a VPC?

To control its cloud network, including addressing, routing, and security.

What is a subnet?

A smaller network segment created within a larger network.

Why divide a VPC into subnets?

To organize resources and separate workloads by purpose or security needs.

What is the difference between a public and private subnet?

A public subnet can have a route to the internet; a private subnet does not have direct internet routing.

Why place sensitive resources in private subnets?

To limit direct internet exposure and reduce unauthorized access.

What is VPC peering?

A private network connection between two VPCs that allows them to communicate.

Why use VPC peering?

To let resources in separate VPCs communicate privately.

Can VPC peering automatically connect every VPC in an organization?

No. Peering connections are generally configured between specific VPC pairs.

What is a transit gateway?

A central network hub that connects multiple VPCs and other networks.

How does a transit gateway differ from VPC peering?

It centralizes connections instead of requiring separate pairwise connections.

When is a transit gateway especially useful?

When an organization needs to connect many VPCs or networks.

What is routing?

The process of selecting paths for network traffic to reach its destination.

What does a router do?

It forwards packets between different networks using routing information.

What is switching?

The process of forwarding data between devices within a network.

How does switching differ from routing?

Switching connects devices within a network; routing moves traffic between networks.

What is a routing table?

A list of rules that determines where network traffic should be sent.

What information does a routing table use?

Destination networks and the next hop or target for traffic.

What happens when a route table has no matching route?

Traffic may be dropped unless a default route provides another path.

What is a default route?

A route used when no more specific route matches the destination.

What is a static route?

A manually configured route that specifies where traffic should go.

What is an advantage of static routing?

It provides predictable paths and does not require route updates from a routing protocol.

What is a disadvantage of static routing?

Administrators must manually update routes when network changes occur.

What is dynamic routing?

Routers automatically learn and update routes using routing protocols.

How does dynamic routing differ from static routing?

Dynamic routing adapts automatically; static routing requires manual configuration.

What is a virtual LAN (VLAN)?

A logical network that separates devices into distinct network segments.

Why are VLANs used?

To separate traffic, improve organization, and limit unnecessary network communication.

Can devices on different VLANs communicate directly by default?

No. Routing is generally required for communication between VLANs.

What is software-defined networking (SDN)?

A networking approach that separates network control from packet forwarding.

What is the control plane in SDN?

The part that decides how network traffic should be handled.

What is the data plane in SDN?

The part that forwards network traffic according to control-plane instructions.

How does SDN simplify network management?

It allows centralized, programmable control of network behavior.

What is Border Gateway Protocol (BGP)?

A routing protocol that exchanges routing information between autonomous systems.

What is an autonomous system (AS)?

A network or group of networks managed under one routing policy.

Where is BGP commonly used?

Between large networks and across the internet.

Why is BGP important for cloud networking?

It helps cloud networks exchange routes with external or on-premises networks.

What does the AS Path attribute in BGP represent?

The sequence of autonomous systems a route has passed through.

How does BGP use AS Path?

It can help select routes and avoid routing loops.

What does Local Preference do in BGP?

It helps choose the preferred outbound route within an autonomous system.

What does a higher Local Preference value generally indicate?

A more preferred outbound route.

What does MED mean in BGP?

Multi-Exit Discriminator; it suggests a preferred entry point into an autonomous system.

How does MED help with routing?

It helps communicate which entry point another network should prefer.

What is the difference between Local Preference and MED?

Local Preference guides outbound route choice; MED suggests inbound entry preference to another AS.

Why might an organization use multiple network paths?

To improve availability, provide redundancy, and maintain connectivity.

How do load balancing and routing differ?

Load balancing distributes traffic across resources; routing selects paths to destinations.

How do a firewall and a load balancer differ?

A firewall filters traffic for security; a load balancer distributes traffic across resources.

How do a CDN and a load balancer differ?

A CDN serves cached content closer to users; a load balancer distributes requests among servers.

How do a subnet and a VLAN differ?

A subnet divides an IP network; a VLAN creates a logical Layer 2 network segment.

How do VPC peering and a transit gateway differ?

Peering connects specific VPCs; a transit gateway centrally connects many networks.