1.6: Network Topologies & Architectures

Star

Network Topology with a central hub connected to

multiple spokes, used in most large and small networks

Used in airline and telecommunications networks; less expensive for larger networks

In Switched Ethernet networks, the switch is in the middle

Mesh

Network Topology that uses point-to-point connections between every device for redundancy, used in WANs

Full: every node is connected to every other

Partial: some nodes are fully interconnected, and others are not

Provides fault-tolerance and redundancy, but can be complex and costly

Hybrid

Network Topology that is combination of one or more physical topologies

Most networks are designed this way

Spine & Leaf

Network Topology that where each leaf switch connects to each spine switch, and vice versa

However, the leaves and spines themselves do not connect

In top-of-rack switching, each leaf is on the top of the physical network rack

Simple cabling, redundant, fast; however, additional switches may be costly

Point To Point

Network Topology that is a one-to-one connection

Older WAN links use this; can be used to make connections between buildings

Three Tier

Network Architecture that uses three layers: Core, Distribution, and Access

Core: center of the network with web servers, DBs, apps; many people need to access it

Distribution: midpoint between Core and users; communicate across switches and manage paths to end users

Access: where users connect; end stations, printers, etc.

Collapsed Core

Network Architecture similar to three-tier, but combines Core and Distribution layers

Good for small and medium sized networks; multiple buildings or campus configs

Costs less and simple to deploy; however, limited scalability, and less devices means less redundancy

East West

Traffic Flow for traffic between devices in the same data center

Relatively fast response times

North South

Traffic Flow for traffic involving ingress and egress to outside devices

Different security posture than traffic between devices in the same data center