Unit 5

Chapter 2

LAN Topologies

Bus Topology

Ring Topology

Ring: Token Ring

Star Topology

Mesh Topology

Mesh: Full vs Partial Mesh

Hybrid Topology

Physical vs. Logical

Now we go one layer deeper.

A bus is a linear network – both physically and logically.

A star topology is physically a star (think of a hub or switch at the center of a group of hosts.

But a star topology in Ethernet physically looks like a start – but at the logical level, the way it actually functions, it uses a bus topology. Think of it this way: if you took all the wiring out of a hub and laid it out, you’d find it’s actually arranged as a bus.

This creates a “Physical Star but Logical Bus” topology. Ethernet hubs and switches use it, but so do Token Ring concentrators.

Wireless Networking

Wireless NICs

Access Points (APs)

Wireless Bridges: Point to Point / Point to Multipoint

Wireless Networking Software

Modes: Ad-hoc vs. Infrastructure

BSSID: Basic Service Set ID (the WAP’s MAC)

SSID: Service Set ID (the network name with a single WAP)

ESSID: Extended Service Set ID (the network  name for a network with multiple WAPs)

CSMA/CA

Wireless Networking Security

802.1x (usually using RADIUS)

MAC Filtering

WEP

64 bit encryption
Shared, static key

WPA

128 bit encryption
Key variants: Enterprise 802.1x vs. Personal PSK

WPA2

WPA3

WPS (DANGER DANGER!!)

Exercise:

WAP Configuration