Ethernet start and end (how to find)

Discussion in 'Mac OS X Server, Xserve, and Networking' started by rickeames, Sep 11, 2018.

  1. rickeames macrumors 6502

    Joined:
    Mar 12, 2008
    #1
    Okay, this is completely not a Mac oriented question, but I was hoping someone knowledgable could point me in the right direction. In my master bedroom, I have a port in the wall for ethernet, as do all of the rooms. Downstairs, I have a master box that all of those cables come into and I can't for the life of me figure out which cable goes to which outlet and I wasn't left with a map.

    What is the best way to create that map? Is there some tool that I can connect to the master plug and then attach to each cable to figure out which one it really is (and thus be able to create a map?).

    Thanks ahead of time!
     
  2. belvdr macrumors 603

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    Aug 15, 2005
    Location:
    No longer logging into MR
    #2
    A cheap switch and a laptop with an ethernet connection would work. Disconnect all rooms. Plug the laptop into a port in a room, and then, using a cable, connect it from the switch to each port in the master box. When it links, you've mapped the first port.

    Do the same for the rest of the rooms and you'll have your map.
     
  3. techwarrior macrumors 65816

    techwarrior

    Joined:
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    Location:
    Colorado
    #3
    The "Master Box" is either a patch panel (no LEDs), or a network switch (LEDs for each port).

    If it is a switch, the LED will light up whenever a live client is on the other end. So, have one person down at the box, another with a laptop walking from room to room connecting to the outlet. As each room is connected, note the LED that lights up on the switch. Use cell phones to communicate if distances warrant, and mark each port such as 1A (Port 1, Room A), 2C (Port 2, Room C), etc. Put a small label on each end and then use a spreadsheet or handwritten document indicating 1A is the Master Bedroom, etc.

    That said, what is gained other than proving the wiring is functional? Ethernet paths are "virtual" in that the switch will sense what MAC Address is connected on the other end, and it's IP Address in order to maintain an ARP cache. when a connection needs to be made to a given client, it looks in it's ARP table to determine which port to send the data to. This is also how the switch determines where the router is, when a request for an external IP is made, the ARP table "learns" where the router is. and forwards these requests to the router.

    If however, the Master Box is simply a patch panel (no LEDs) it will require another ethernet connection back to a switch or router. If this is the case, then I can see the merit of knowing where each port goes if you don't have a switch with enough ports for every room and won't be using ethernet in every room. In this case, a network switch with one cable going to the Master Box starting with Port 1, and a laptop on the other end. The switch will light up when a connection is made to the laptop. Same labeling.
     
  4. hobowankenobi macrumors 6502a

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    on the land line mr. smith.
    #4
    Per Techwarrior.....what problem are you trying to solve?

    Typically everything is plugged in and all ports are live. If so, why bother to map?
     
  5. rickeames thread starter macrumors 6502

    Joined:
    Mar 12, 2008
    #5
    I need to map because the panel didn't have enough ports to handle all of the wires. Most of the house runs wirelessly, but at some points, I would like wired. For whatever reason, the master never gets a signal, so I want to identify which wire it is and figure out a strategy.
     
  6. belvdr macrumors 603

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    #6
    Can you take a picture of the master box you refer to?
     
  7. Howard2k macrumors 68020

    Howard2k

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    Mar 10, 2016
    #7
  8. hobowankenobi macrumors 6502a

    Joined:
    Aug 27, 2015
    Location:
    on the land line mr. smith.
    #8
    Sounds like the "panel" is a patch panel.

    several ways to go, but a pic would be helpful.
     
  9. techwarrior macrumors 65816

    techwarrior

    Joined:
    Jul 30, 2009
    Location:
    Colorado
    #9
    I think 20 questions has us to the point that the Master box is a patch panel. Something like this?

    Are you saying there are additional Cat5e\Cat6 cables from rooms that don't terminate on a port on the panel? If so, put an RJ45 on the end of the spare leads and plug them into a network switch big enough for all of the rooms, including the ones going to ports on the panel. With one switch port for each room, you don't really care what is on the other end as long as a connection can be made.

    If the wires got pulled out of the panel, that could cause ports to be faulty. Check the wiring, get a punchdown tool and reseat the leads on the back of the panel. If you live in humid climate, corrosion may cause poor connections so reseating the leads can resolve it. But, be very careful to get the right leads. Cat 5\5e\6 cables are color coded and must be connected to the right pins or all bets are off.

    If the problem is in the wires behind the walls, less options if someone drove a nail through a cable. If you really need Ethernet to rooms with faulty wiring, Powerline adapters are an option.
     
  10. mmomega macrumors 68030

    mmomega

    Joined:
    Dec 30, 2009
    Location:
    DFW, TX
    #10
    You can find cable testers online or at Home Depot/ Lowes that you can connect a small device on one end of an ethernet cable then when you connect the test to the opposite end the tester will show that there is a connection plus the small device will make an audible tone. A lot of times known as "toning out lines"

    You can then get either a label make or just masking tape and label each line as you figure out to which room they go to.

    Just do a search for network cable tester. They usually will be able to test normal ethernet cable, phone line, coax.

    One will run you from around $25 to $100 to higher depending on the functionality you want.
    Hope this helps.

    Mine looks like this.
    The bottom pops out from the tester.
    Connect an ethernet cable to that side.
    Take the main unit to where all of the cables run in together.
    Turn on tester.
    Connect a cable, press test.
    If no tone, disconnect from tester, move on to the next cable. Repeat until you get a tone.
    Label cable.
    Repeat.
    Screen Shot 2018-09-16 at 8.10.01 PM.png
     
  11. Altemose macrumors G3

    Altemose

    Joined:
    Mar 26, 2013
    Location:
    Elkton, Maryland
    #11
    Many Ethernet tone generators do not even need to be connected to the port, only hovered over top.
     

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10 September 11, 2018