Network help, switch and router on same network?

Discussion in 'Mac Basics and Help' started by rhett7660, Mar 17, 2010.

  1. rhett7660 macrumors G4

    rhett7660

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    #1
    Hello...

    I have a question. I am currently using a 10/100 router that is connected to the internet and has 8 ports. However I want to take advantage of my 1000 cards on my machines within my home network for transfering files back and forth. So here is my question. If I purchase a switch (10/100/1000), can I have the switch connecting my machines and then have the switch connect to the router to get to the internet? Is this possible? Or do I need something else?

    Setup:

    Mac's and windows machines--->switch--->router?

    Thanks
     
  2. spinnerlys Guest

    spinnerlys

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    #2
    As far as I know, if a 10/100 Mbit device is connected to a Gigabit switch, the whole network gets down to 10/100 Mbit/s speeds.

    Better look for a Gigabit ethernet router with some ports.
     
  3. velocityg4 macrumors 68040

    velocityg4

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    #3
    That is handy to know. It was driving me crazy wondering why all my Gigabit computers were connecting at 100 mbit. Since I have a 10/100 switch hooked up for my older devices while my router is 10/100/1000.

    Though now there is no solution as I want my 10/100 devices to connect still.
     
  4. spinnerlys Guest

    spinnerlys

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    #4
    That reminds me, even a modem will slow the speed down, as they use 10/100 Mbit/s ports.

    That's quite a drag.
     
  5. rhett7660 thread starter macrumors G4

    rhett7660

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    #5
    Just to clarify, your network speed will go the fastest of the slowest appliance on the network? Just confirming. Well that just sucks. LOL.. Heck.

    Will it also be limited to what speed it is connecting to the internet? Just trying to figure this out.
     
  6. spinnerlys Guest

    spinnerlys

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    Yep. If only one device is 10/100 Mbit/s, all the hundreds of other Gigabit devices you might have connected will slow down. Nice, eh?
     
  7. belvdr macrumors 603

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    #7
    No, that is not the way it works. That would provide no path for migration to faster speeds.

    Very very incorrect. This isn't USB or SCSI. :)

    It only goes as fast as the slowest link in the path of communication in a switched environment.

    So let's say you have two PCs linked at gigabit, and your router is connected at 100Mb into the switch and has a 15 Mb line to the Internet.

    If either PC connects to the Internet, they will be limited by the 15Mb line. If they are communicating to each other, they are limited to gigabit.
     
  8. rhett7660 thread starter macrumors G4

    rhett7660

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    #8

    Ok,,,,, So if I have a switch (I have been looking at routers for 8 ports and they are just a tad expensive with 10/100/1000) that my computers are connected to. All my machines have 1000 on them. They should in theory be connecting to each other at the 1000 range. If the switch in turn is connected to the router, what ever speed going out will be the limit. Does this make sense? Am I saying it correctly?


    Edit, we are posting at the same time LOL....
     
  9. belvdr macrumors 603

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    #9
    Yes, that is correct. The slowest link in the path of communication (server to server is gigabit, server to internet is usually the Internet link) is the limit.

    I'd check out some Netgear or Linksys switches. They are much less expensive since you lose the advanced management features of say Cisco.
     
  10. spinnerlys Guest

    spinnerlys

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    #10
    [​IMG]
    I'm confused, the slowest link determines the fastest speed? Isn't that what I was talking about?
    Sorry, English is not my first language, so I may misunderstand something here.


    / [​IMG]

    Do you have some documentation on this?

    As I have experienced it otherwise and read it like I described, but I like to be proven wrong with this.

    I have a 10/100 Mbit router, a 10/10 Mbit iBook and three Gigabit capable Macs. I also have a Gigabit switch (Netgear I think), and if the Gigabit devices are connected to the Gigabit switch I get 40 to 70MB/s, but once I connect my iBook or/and router, the speed goes down on all of the Macs, Gigabit Macs included.

    Might that be just a problem with my Gigabit switch? I bought it a year ago, and when I discovered this nice disability, I looked on the www and found some "evidence/written testimonials", that it is indeed that way as my switch does behave.

    But as I said before, I like to be proven wrong on this issue.
     
  11. rhett7660 thread starter macrumors G4

    rhett7660

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    #11

    Just for clarification:

    10/100 router which is connected to a 10/100/1000 switch.

    Connected to the switch you have:
    10/100 ibook
    (3) 10/100/1000 Macs

    When you connect the iBook everything on the network that is connected to the switch with the iBook, they all drop down in speed to match the iBook? Doesn't matter if you are transferring files from the 10/100/1000 Macs and not transferring any files to the iBook, just going between the Macs?

    Just clarifying.
     
  12. spinnerlys Guest

    spinnerlys

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    Assumption is correct. Right now though I have disabled my cable network as I don't have that much of a need due to many external HDDs, but when everything was connected, I couldn't transfer at gigabit speeds anymore, even between Gigabit devices. The switch even changed the status light, from green (gigabit) to yellow (10/100).
    That's why I told you what I wrote, as I informed myself, but may have done so wrongly.

    We'll see.
     
  13. belvdr macrumors 603

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    #13
    What you were saying is plugging a 10 Mb device into a switch impacts all other systems on that switch, even if they connect at a higher rate. What I'm saying that you are only limited by the slowest link in the path of communication.

    For example, at work I have hundreds of switches. Some are 10/100 and others are 10/100/1000. If I plug a device into port 1 and link it at 10 Mb and half-duplex, it has zero impact on another device plugged into any other port, unless I have to go through that device on port 1 to communicate to another device. Quite frankly, it is common to have 48 ports linked at 100 Mb to clients and have that switch link at gigabit back toward the servers.

    If you experienced your anecdote on a switch, then you have a faulty (or a very cheap implementation of a) switch.

    EDIT: Here's a link from Cisco that discusses how switches work. This goes way beyond the scope here, but it is possible to not get the full throughput on a switch due to oversubscription of ports (i.e. 8 gigabit ports share a one gigabit connection back to fabric of the switch), but you should never see this on an 8 port switch.
     
  14. Queso macrumors G4

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    #14
    In an unmanaged switch each port runs at whatever speed it can negotiate with the connected device. If you have a gigabit interface in your Mac and you plug it into a gigabit-capable port on the switch then they will connect at gigabit. This does not change even if you plug a 10Mbps printer into the next switch port over. The switch will talk to the printer at 10Mbps and still allow the Mac to talk at gigabit.

    So if you have two gigabit Macs and you transfer files between them via the switch they will do so at gigabit speeds, even if you also plug in a 100Mbps iBook. File transfers to and from the iBook will only run at 100Mbps, but otherwise the slower speed will not affect the transfer speed between the gigabit devices.
     
  15. rhett7660 thread starter macrumors G4

    rhett7660

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    #15
    So you could have in theory a computer running 2Mb on the switch and as long as your data doesn't have to go to or through the 2Mb stream it will go at what ever speed you are transmitting at.

    IE
    Switch
    1 10MB box
    1 1000Mb box
    1 1000Mb box

    Transferring files from 1000 to 1000 no slow down. But as soon as I send something to the 10Mb it slows down the 1000Mb. What about if I have a file going to both 1000Mb and the 10Mb, via a switch, would the file slow down to the 10Mb or would it slow down on just the 10Mb box but continue at a much higher speed to the 1000Mb?
     
  16. spinnerlys Guest

    spinnerlys

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    Ah, thank you. I must have a faulty one, I grab it and try it when I have time again.

    I have a low consumer Gigabit switch with 5 ports, thus it might be understandable.

    I had a 16 (or have?) port 10/100 switch before and when I connected 10 Mb devices, I still got 100 Mb with all the other computers, if I remember correctly. Should have thought of that, completely forgot it, but it was five years ago and today almost everything I do with networking is wirelessly

    Thanks again for proving me wrong, and for the link.*




    * Nice, something technical. My mind just got a little bit ... wet. That reminds me of my studies (not network topologies as one might gather from my "vast" knowledge), when we had diagrams and graphics like these. Shame that I understand them better now.
     
  17. belvdr macrumors 603

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    #17
    Your second statement is correct. No one port has any impact on another port in a totally switched environment.

    Let's assume ideal throughput for easy math and that there's no contention between transfers.

    Let's call the machines 10_A, 1000_A, and 1000_B, where they connect at 10Mb, 1000Mb, and 1000Mb, respectively.

    If 1000_A copies a file to 10_A and consumes the entire 10Mb of bandwidth on 10_A, then 990Mb is remaining for other tasks.

    In reality, you'd get less than that, but that's the theory behind what happens.
     
  18. rhett7660 thread starter macrumors G4

    rhett7660

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    #18
    belvdr

    Thank you very much. One more question for yeah.

    I can mix switches and routers together correct?

    1 switch
    1 router

    Computers are connected to just the switch
    The switch is connected to the router
    router connected to internet

    I can do this correct? So if my router is 10/100 but my switches are 10/100/1000 and I am just transferring files between the computers and not going to the internet they should do it at the highest speed. But as soon as I go to the internet what ever speed the router is topped out at is what I will get? Is this correct?
     
  19. belvdr macrumors 603

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    #19
    That is correct. If you have a somewhat intelligent switch (i.e. like using another router's built-in switch without using the WAN port), it may have DHCP on it. If so, disable DHCP on one of the devices, as you only want one active DHCP server on any given subnet.
     
  20. rhett7660 thread starter macrumors G4

    rhett7660

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    #20
    Perfect. Thank you very much for explaining this. I was looking and reading but the way it was explained here is great!

    Thanks again
     

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