Describe characteristics of network topology architecture

Two-tier

• Consists of the Access Layer and Distribution Layer

• Distribution Layer acts as Core Layer as well

• Used when the network does not require the scalability and performance of a dedicated Core Layer

SCRIPTRI

• Simplicity

• Cost-effective

• Redundancy

• Inter-VLAN Routing

• Performance

• Traffic Filtering

• Route Summarization

• Increased Scalability

Three-tier

• Consists of Access Layer, Distribution Layer and Core Layer

• Used in large enterprises and networks where scalability and performance are critical

• Access connects, Distribution controls, Core transports

HSRP-RTH

• Hierarchical design

• Scalability

• Redundancy

• Performance

• Route summarization

• Traffic filtering

• High availability

Spine-leaf

Servers connect to leaf switches, leaf switches connect to spine switches, spine switches connect only to leaf switches

Leaf Switch:

• Connects end devices

• Provides Layer 2 and 3 connectivity

• Forward traffic to spine layer

Spine Switch:

• High speed packet forwarding

• Provide multiple paths

Used in:

• Data Center

• Cloud

• Virtualization

• Kubernetes

• East-West Traffic

• ECMP

WAN (Wide Area Network)

A WAN connects geographically separated networks using service provider infrastructure to enable communication between remote locations.

Key characteristics:

• Large geographic coverage

• Interconnection of multiple LANs

• Reliance on service provider infrastructure

• Scalability

• Support for remote access

• Redundancy

• Security mechanisms

• Use of routers for connectivity

• Enable communication between remote locations

• Higher latency

• Greater complexity

Used in:

• Branch offices

• Campuses

• Data centers

• Remote users

SOHO (Small Office/Home Office)

A SOHO network architecture is a small, cost-effective network that provides Internet access, resource sharing, and basic security for home users and small businesses

Key Characteristics:

• Small scale

• Simple design

• Integrated networking devices

• Wired and wireless connectivity

• Internet sharing through NAT

• DHCP services

• Basic security features

• Resource sharing

• Limited scalability

• Usually all in one router

On-prem

An On-Premises network architecture is a network model where servers, storage, applications, and networking devices are located and managed within the organization's own facilities.

Key characteristics:

• Full control of infrastructure

• On-site hardware

• Higher initial costs

• Greater responsibility for maintenance

• Enhanced control over security

• Limited scalability.

Access Layer

The access layer is where end devices connect to the network, providing network access to users and end devices.

Functions:

• VLAN assignment

• Port security

• PoE

• Layer 2 switching

Distribution Layer

The distribution layer aggregates access switches and performs policy-based connectivity.

Functions:

• Inter-VLAN routing

• ACL (Access Control Lists)

• QoS (Quality of Service)

• Route summarization (Summarizing routes e.g. /24 to /16)

• Traffic filtering (Allow/deny based on predefined rules)

• Redundancy (Providing backup devices, links, or paths in a network)

Core Layer

The Core Layer serves as the network backbone and provides fast, reliable transport between distribution layers.

Its primary goals are high availability, high-speed forwarding, and rapid convergence with minimal processing.

Cloud

A Cloud network architecture is a model where computing resources and services are hosted by a cloud provider and accessed over the Internet.

Key Characteristics:

• on-demand access,

• high scalability,

• pay-as-you-go pricing,

• reduced maintenance requirements,

• high availability,

• global accessibility