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Networks Ethernet extension - works for some devices

Discussion in 'Tech Support' started by mrMonkeyChunks, 9 Aug 2020.

  1. mrMonkeyChunks

    mrMonkeyChunks EVGA Cheesecake

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    Hi there,

    Wondering if anyone with more networking knowledge than me could me out.

    I have recently bought a flat that has ethernet in the walls, however I can't get this to work properly.
    I have a virgin super hub 4 sitting in my living room where the cable comes into the property, this is then connected into the wall socket. So far this all works fine, I can get a connection on my pc when plugged directly into the hub.

    The issue is that from the other end of the ethernet run in the bedroom I can only get a network connection on some devices.
    For example my work aptop (a thinkpad T480s) seemingly works fine when connected to the ethernet port in the wall, but using the same cable plugged into my main PC just shows as 'network cable unplugged'

    The PC works fine when plugged into the hub directly with the same cable so it doesn't appear to be a hardware issue (i also loaded up Ubuntu and that couldn't connect from the bedroom either). I've tried cmos resets, driver reinstalls as well with no luck.

    Any idea why some devices appear to function fine and others not at all?
     
  2. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

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    Back in the day, I would have said it's the symptoms of someone having wired the socket up as a crossover rather than a straight-through connection - but any piece of IT gear made in the last couple of decades does auto-MDI, meaning it can detect whether it should be crossover or not and "rewire" itself accordingly.

    It could still be a wiring problem, where something's marginal or miswired in such a way that it's only affecting certain devices. First port of call would be to hook a cable tester in there and see if it's wired up right.
     
  3. Xlog

    Xlog Active Member

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    You might need to open the sockets and check the wiring, had similar problem once where someone wired the sockets without bothering to keep correct wire order ( both ends were wired the same, so cable tester showed ok).
    It might also be that builder cheaped out and laid CCA cable.
    Ethernet in the walls (especially under plaster) is the worst to diagnose and if it was laid by construction crew and not by IT personnel - expect a lot of problems.
     
  4. Andersen

    Andersen Brain for hire

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    Wireless on those definitely-not-super hub 3s is a bucket of **** thanks to crappy chipset.

    I'm heavily biased towards Asus routers, cheapest first:
    AC51U
    AC750
    AC1200
    AC1200 dual band
    AC2400

    First one should do you just fine but pricier models come with more features and higher wireless speeds.

    Edit: like other said, check the wiring, cable testers go from £10 or so up and will tell you if the connections are ok.
     
  5. mrMonkeyChunks

    mrMonkeyChunks EVGA Cheesecake

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    Thanks guys, I bought a cable tester and it looks like there may be a fault with line 4 which I'll try to correct by rewiring the bedroom socket.
    My understanding was that line 4, solid blue, was actually used for data transfer, that these are handled by the orange and green pairs?

    Also worth noting that the socket in the living room was wired to t568A and the other to t658B so my faith in the installation team is limited to say the least.

    The network connection did suddenly work on my main desktop last night though (prior to any repairs to line 4) although it only ran at 10Mbps line speed for some reason where as the laptop gets 100Mbps line speed (I assume the laptop has a 100/10 port) which falls well short of the 200+Mbps when plugged directly to the hub.

    I do have an older Asus RT N66U somewhere at the parents house that I could try to get a hold of, although given its relative age and the flats configuration a mesh system or more powerful, modern router may be needed for half decent speeds
     
  6. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

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    Gigabit Ethernet requires all four pairs to be wired up correctly, or it'll fall on its bum-bum; 10/100 is a lot more forgiving of wiring mistakes/failures.
     
  7. mrMonkeyChunks

    mrMonkeyChunks EVGA Cheesecake

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    Well, with the help of my shiny new IDC punch down tool I've rewired all the sockets as I don't trust the original installation at all.
    Also replaced or redid all the external cables for good measure.

    And everything works now! Getting just over 220Mbps and 20 up to the bedroom now.

    Now to get an AP or something for wifi in here too....

    Thanks for all the help guys, glad that headache is solved.
     
    Arboreal, modd1uk and ElThomsono like this.

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