# Core Concepts and Design

> Markdown source of <https://docs.calebsargeant.com/networking/cisco/switching/core-concepts-and-design/>.

## Plug and play switches

- Chance for failure
- Broadcast traffic
- Multicast issues
- Security issues
- MAC flooding

## Enterprise Composite Network Model

- Access
- Distribution
- Core

## VLANs

- Simpler Management
- Troubleshooting ease
- Better performance
- Mental sanity
- Summarization points

## Designing the Network

- Restrict VLANs to switch blocks
- Implement management VLAN
- Separate voice traffic
- Implement multicast support

## The Two Flavours of CISCO Switches

- CISCO catalyst OS (CatOS)
  - Uses set-based syntax
  - Typically combined with IOS for layer 3 functions
- CISCO 'native' IOS
  - Similar to router configuration
- Typically, all larger switch models (such as cat 4500, 6500, etc...) run CatOS
- CISCO has a migration path for all mainline switches to the native IOS