Broadcast Domains and Collision Domains

Collision Domains
  • Separated by switch/bridge interfaces
  • A historical footnote
    • It's difficult to find a collision these days
    • The word *collision" is misleading
  • The network was one big segment
    • Everyone heard everyone else's signals
    • One big conference call
  • Only one station can "talk" at a time.
    • Is the line clear? Ok, I can talk.
    • Carrier Sense Multiple Access (CSMA)
  • When two people spoke at the same time, there was a collision
    • Collision Detection (CD) - Send the jam signal


Broadcast Domains
  • Separated by router interfaces
  • Spread the word!
    • Everyone must know!
    • ARP probes, operating system notifications
  • How far ca a broadcast go?
    • Passed by a switch/bridge
    • Stops at the router
  • This can be important
    • More devices, more broadcasts

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