Chapter 42 - LAN Architecture

Question 1

What is a Campus LAN?

Answer 1

• A LAN created to support devices in a building/buildings in close geographical proximity to each other.

Question 2

What is a Collapsed Core LAN design?

Answer 2

• Two Tier Campus Design
• Only has Distribution and Access layers
• Distribution and Core are sometimes merged to create the Core-Distribution layer

Question 3

What is a Two Tier Star design?

Answer 3

• A design in which one central device connects to several other devices

Question 4

What is a Two Tier Full Mesh design?

Answer 4

• A design in which a link exists from every networking device to every other networking device.

Question 5

What is a Two Tier Partial mesh design?

Answer 5

• A design in which a link exists from every networking device to some other networking devices.

Question 6

What is a Two Tier Hybrid design?

Answer 6

• A design that combines ideas of multiple different architectures into one single design

Question 7

What is a Core LAN design?

Answer 7

• Three Tier Campus Design
• Has Core, Distribution, and Access layers

Question 8

How many Distribution Layers can you have in a Campus before it is recommended to add a Core Layer?

Answer 8

3

Question 9

What is North-South and East-West traffic?

Answer 9

• North-South is traffic that goes from Access, to Distribution, to Core layer devices and vice versa
• East-West is traffic that remains in its layer. Normally Access layer devices communicating

Question 10

What is Spine-Leaf architecture?

Answer 10

• Normally implemented in data centres
• Also known as Clos architecture or Application Centric Infrastructure
• Used to rectify bottle necks caused in three tier architecture as well as variability in East-West traffic depending on the path it takes. In Spine-Leaf, the path is randomly chosen to balance the load among Spine switches
• Each host is separated by the same number of hops apart from those connectect to the same Leaf (which have less)
• 2 tier design
• Leaf is comparable to Access and Spine is comparable to Distribution/Core
• The rules of thumb are:
  - Every Leaf switch is connected to every Spine switch and vice versa
  - Leaf switches do not connect to Leaf switches and Spine switches do not connect to Spine switches
  - End hosts only connect to Leaf switches

Question 11

What is another name for Cisco ACI (Application Centric Infrastructure)?

Answer 11

Spine-Leaf architecture