I joined together a CAT5E cable and a CAT6 cable with a pair of CAT6 keystone connectors, but the cable does not function well. When I try to ping my router while using the cables, I get a lot of time out errors.

What could be wrong?

To try and draw this out:

(--CAT5e---)(Cat6 keystone connector)(very short cat6 cable)(Cat6 keystone connector)(--CAT6---)

So there's a total of three wire segments:

  1. Cat5e with RJ45 on both ends
  2. cat6 (punched down in between two cat6 keystone punchdown female jacks)
  3. cat 6 with RJ45 on both ends

I have a cable pin tester and each segment tests perfectly fine. It's just that when all of it's put together, the cable pin tester gives me errors.

I know it's a weird/crazy setup but it's all the parts I had on me at the time.

  • Can you provide us the errors?
    – Ramhound
    Aug 31, 2017 at 3:52
  • 1
    A pinout tester won't tell you if you've split a pair. Split pairs ruin signal integrity. Remember, pin 3 is in a twisted pair with pin 6, not pin 4. Pin 4 is twisted with pin 5. You can get this wrong and still have the pinout come out right, because a typical cheap pinout tester can't tell which wires are twisted with which other wires
    – Spiff
    Aug 31, 2017 at 4:44

2 Answers 2


It's just that when all of it's put together, the cable pin tester gives me errors.

What could be wrong?

Two possibilities:

  1. One of the components in your string of connections is miswired. They should all be wired straight-through.
  2. One of the components is defective/not making a good connection.

You shouldn't be wiring something up like this. If you want your network connection to work reliably, you should use best-practice wiring methods. Use of couplers and (though you don't mention it) possibly stiff network cable that's only meant for in-wall installation is asking for errors like this.


Some hints:

  • When you punch your cables, the untwisted part should be very short, gigabit Ethernet is very sensitive to that.
  • Beware of the T568A vs T568B problem, those two type of cabling exist and can't be mixed.
  • Forcing the link speed down to 100MBit/s can also be a temporary fix.

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