Broadcast Collision Domains?

Discussion in 'Windows Desktop Systems' started by Eagle710, Oct 16, 2007.

  1. Eagle710

    Eagle710 OSNN Senior Addict

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    HI i was trying to figure out the difference but i can seem to find a good definition of either of these terms. Broadcast Domain .... Collision Domain. I have been trying to learn it but it wont make sense to me when i read it off Google searches. Anyone can please offer me some help with a nice easy to understand definition please. I would appreciate it.

    Eagle710
     
  2. celticfan11

    celticfan11 Moderator

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    Imagine you have a the following setup

    .........Router
    ........../.....\
    ....switch...switch

    there are 2 broadcast domains in the above crude diagram, because layer 3 devices(routers) DO NOT forward broadcasts. Only layer 1 (hubs) and layer 2 (switches) do. A Broadcast domain is only segregated by a layer 3 or higher device that will not forward the broadcasts. So Each switch is its own broadcast domain. Make sence?

    A collision domain, is basically non exsistant today. Basically it is any segmant where collisions can happen. You cannot have collisions on a layer 3 device or a layer 2 device. So each port on a switch is a collision domain. a layer 1 device (hub) WILL be a big collision domain because packets can cause collisions due to i want to say being half duplex. I think i am wrong there. But a 24 port switch will have 24 collision domains.

    Hope i helped.
     
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  3. kcnychief

    kcnychief █▄█ ▀█▄ █ Political User Folding Team

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    Thread moved
     
  4. fitz

    fitz Just Floating Along Staff Member Political User Folding Team

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    Well, to be a little more particular, as each collision domain is a segment, a port is not a segment, the segment would be the connection from one port to another port on a switch, meaning, each port on a 24 port switch could technically take part in up to 23 collision domains (1 collision domain for each "segment" to the other ports on the switch) :p
     
  5. Eagle710

    Eagle710 OSNN Senior Addict

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    Broadcast Domains i get but im stilling have difficulty understanding which devices allow or cause collision domains?? Thanks all for your tutoring lessons.
     
  6. fitz

    fitz Just Floating Along Staff Member Political User Folding Team

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    Basically, only a hub will allow a collision domain. Generally, who uses hubs anymore? Don't use a hub.. buy a switch..
     
  7. celticfan11

    celticfan11 Moderator

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    im assuming this is for school.....
    a Hub = one big collision domain.
    a switch = Many collision domains
     
  8. fitz

    fitz Just Floating Along Staff Member Political User Folding Team

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    and in this case, one big collision domain is a bad thing..
     
  9. Eagle710

    Eagle710 OSNN Senior Addict

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    Yeah this is for school i got Cisco test coming up and the stupid book doesn't explain these details very good. So i thought i would Google which didn't settle properly in my head but OSNN did so.... Thank you
     
  10. X-Istence

    X-Istence * Political User

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    Cisco test eh? Good luck!
     
  11. celticfan11

    celticfan11 Moderator

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    those are fun :)
     
  12. Eagle710

    Eagle710 OSNN Senior Addict

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    Yeah... my teacher is dumb as can be though
     
  13. kcnychief

    kcnychief █▄█ ▀█▄ █ Political User Folding Team

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    I think both Mike and myself can relate to that one ;)
     
  14. Eagle710

    Eagle710 OSNN Senior Addict

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    Did the test and thanks to your help with BCs and DCs help i was able to answer the question... of course doesnt mean i got it right. LOL... we will see in two weeks. Thanks again all
     
  15. celticfan11

    celticfan11 Moderator

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    ha ya we can
    but now i actually know cisco :)