10 votes

Home network support: Setting up a network switch

I moved into a new apartment and was surprised to see that all my rooms have CAT 5 Ethernet ports in the wall. However, cue my disappoint when I try to naively plug my router and machine in two separate ports to find that the ports don't actually work. After searching various forums, I found that I have to:

  1. Locate the panel where all the ethernet ports connect
  2. Wire them to an ethernet switch.

I found the panel but all the wires look like this:

https://i.imgur.com/Qzm72g0.jpg

I'm not sure what I need to do from here to plugging into my network switch. Any guides or advice would be extremely helpful. I don't need every port connected to the switch, only one or two. None of these look labelled so I might have a difficult time isolating which cable runs where.

And about the network switch... Any qualms about using an old router that has the AP turned off?

6 comments

  1. PendingKetchup
    Link
    Yeah, that's definitely wired for phone instead of Ethernet, with only a single pair from each cable hooked up, but you can probably upgrade it. I guess they used Cat5 cables and Ethernet-sized...
    • Exemplary

    Yeah, that's definitely wired for phone instead of Ethernet, with only a single pair from each cable hooked up, but you can probably upgrade it. I guess they used Cat5 cables and Ethernet-sized jacks because you can push multiple phone lines over the same cable, and still plug in a normal phone cord in the bigger plug. Or maybe because they figured they might eventually want Ethernet.

    As far as supplies, I would recommend getting a whole kit something like this one, including the Ethernet cable ends, the crimper tool, and the tester tool to make sure you actually did it right. I can't speak for this partticular kit, but that tester looks exactly like the one I have, and I like it. You plug the big box in at one end of the cable, the little box in at the other, and the lights on both light up in the same sequence if the cable is good and all the wires are matched up on both ends.

    On the end you posted the photo of, I would just cut off the piece with the jacks that everything is hooked to, and put normal Ethernet ends on all the cables coming in. You thread the wires into the plastic end bit in one of the orders specified here, and then crimp it down with the crimp tool. You might want to practice on a piece of cable that isn't in your wall until you can make a cable that the tester likes, and that you like; I always have trouble getting the inner wires cut to the right length, so they don't stick out the back of the plug without their outer insulation. I'd recommend getting cable ends that look like this, where you can stick the extra wire length out the end and then trim it off, because then you don't have to worry about getting things cut to the right length beforehand.

    Where you might run into trouble is if the wires at the far end, attached to the room jacks, aren't in the right order. I'd recommend opening up one of the boxes and looking at the color-order of the wires there, and seeing if it matches either T-568A or T-568B ordering as shown in the diagrams I linked earlier. If it matches one of them, then use that same ordering on the far end of the cable, and you'll get a straight-through, normal Ethernet cable all the way from one end to the other. If it doesn't quite match either spec, but you can make it match by reassigning the colors (e.g. they've swapped solid and striped green with solid and striped brown, respectively, or they have swapped solid and striped orange with each other), you can do the same swap at the other end and get a working cable. Inside the cable, the solid and striped wires of each color form a twisted pair, and you can freely reassign which pair is which, or which wire of the pair is which (in a consistent way on both ends), as long as wires that want to be paired with each other stay paired with each other.

    If whatever they've done at the other end bears no discernible relation to the Ethernet cable standard, or if the other end also only has two wires connected, you'll have to fix up those ends too.

    And if all you really want is to run one Ethernet signal through this whole mess, in the junction box where everything comes together you can put an Ethernet coupler and connect together the cables for the two rooms you want to connect, directly. As long as the total length of both cables is <100 meters, this will just be a single long to-spec cable and one end can connect to your router and the other to your computer, without needing any powered equipment at the junction box.

    If instead you want to use a router in the junction box, as a switch, make sure you turn off its DHCP server, so it doesn't try to run your network at the same time as your main router does. You can also just put your main router in there, and use one of the cables to connect it to your modem in another room.

    If you have $60 but no good way to bring power to where the junction box is, but you still want a switch in it, you can get a switch that is powered by power-over-Ethernet and bring power and data to the switch over the same Cat5 cables that are already there. You put an "injector" at the other end and plug that into an outlet, and it multiplexes the power and data onto the cable.

    9 votes
  2. [4]
    Weldawadyathink
    Link
    You have a bit of work ahead of you, so let’s start with the easy parts. You can use an old router as a switch, just ignore the wan port. You can also buy a gigabit router with 5 or 8 ports for...

    You have a bit of work ahead of you, so let’s start with the easy parts.

    You can use an old router as a switch, just ignore the wan port. You can also buy a gigabit router with 5 or 8 ports for cheap. This will likely be more power efficient than an old router. Just don’t get one that is “fast Ethernet”.

    It looks like your house is wired with phone lines over cat5 cabling. This means you will have to replace the connectors with 8p8c connectors (often called rj45). You need a crimp tool and the physical connectors. MonoPrice is a good source for these. Look up some videos to get the idea. It seems weird that they would have rj45 plugs on the other side of the cable runs with only a single pair attached on this side. Could you post a picture of the wall Ethernet plugs you plugged into? Also, could you remove those from the wall and take a picture of the wiring?

    5 votes
    1. [3]
      Icarus
      Link Parent
      Thanks for the help! I have a few old routers to choose from so I will have to assess and see if they are gigabit routers. Here are the pictures: 1 2 3 Based on the ethernet port being attached to...

      Thanks for the help! I have a few old routers to choose from so I will have to assess and see if they are gigabit routers.

      Here are the pictures:

      1 2 3

      Based on the ethernet port being attached to a blue cable, I may not be looking in the right place to set up the network switch...

      1 vote
      1. [2]
        Weldawadyathink
        Link Parent
        The top ports are wired for fast Ethernet, the bottom is wired for gigabit. You should try and find the other end of that blue cable. Otherwise, /u/PendingKetchup has a very good reply.

        The top ports are wired for fast Ethernet, the bottom is wired for gigabit. You should try and find the other end of that blue cable. Otherwise, /u/PendingKetchup has a very good reply.

        1 vote
        1. Icarus
          Link Parent
          Thank you so much for your help! Between your's and /u/PendingKetchups write up, I feel a lot more comfortable on the next steps. I'm really curious where the blue cable is ending up. I put in a...

          Thank you so much for your help! Between your's and /u/PendingKetchups write up, I feel a lot more comfortable on the next steps. I'm really curious where the blue cable is ending up. I put in a request with the maintenance team at my apartment so they may be able to point me in the right direction.

          If its inaccessible, I might end up coupling two of the gray cables if I can confidently identify which one leads to the port closest to my router and which one leads to the port in the bedroom. Hopefully it doesn't come to that and the blue cords are accessible and have RJ45 connectors at the end. That would be a dream.

  3. gpl
    Link
    Just as a note, you may be interested in getting a cable tester in order to figure out which cables lead where and to properly label them. You plug one end into the outlet and the other into the...

    Just as a note, you may be interested in getting a cable tester in order to figure out which cables lead where and to properly label them. You plug one end into the outlet and the other into the terminal end of the cable and can figure out which cables lead where. The one I linked is just a random one I found, but look around a bit. You probably want one with one male and one female end. They're very helpful when you're coming into a place with unfamiliar wiring.

    3 votes