Broadcast domain

• Logical division of a computer network
• Nodes can reach each other using broadcast at the data link layer
• A broadcast domain either in the same LAN segment or which can bridge to other LAN networks.
• any computer connected to the same Ethernet repeater or switch is a member of the same broadcast domain.
• routers never broadcast from one Domain to another. ⚠️ router 不參與 !!
• 該網段之主機，能夠接受到廣播封包之網路稱之
• HUB & SWITCH 無法切割廣播網域，需靠ROUTER
• No collision

Collision Domain

• 當兩台電腦，同時搶用共用的媒體，即會產生碰撞。

• 如何降低碰撞問題？

  • CSMA/CD（載波感測多重存取碰撞偵測）。  • 設備的更替

• a network where only one node can transmit at a time

• total network bandwidth is shared among all devices on the collision domain

• 交換器參與