If it's a decent cable tester it should be testing length as well. I do wonder though whether Ethernet cable testing is the main purpose of the tester or if it just happens to have that function as a "value add".

I hate to say it but £100 for a cable tester is relatively cheap. See some of the later posts but does the cable tester do full testing including checking for length or is it just checking the pin-outs?

How would I set this up? Please excuse my lack of knowledge in this department, I am a security engineer by trade.

In the properties of the network card you should be able to set what it negotiates at.

It's just checking the pins, this is just a function on it. It is primarily a CCTV monitor to check picture and telemetry of dome cameras.

No cable length test function.

Yes, same kit, initially with different ports on the switch but have since tested using the same one. All ports have been tested at the switch with the laptop and are all working fine.

Really you need a proper Ethernet tester as that would show up all sorts of potential issues that won't show on the tester you currently have. Testing just for pin-outs is not sufficient for a network install and won't give you anything around the quality of the structured cabling connections.

Without a proper tester you would need to remake the connections until you get to a point where it is working - but even if you get a connection you can't be guaranteed that it is a high quality connection without doing network tests.

OK, thanks a lot for the advice. It looks like I'll have to hire a decent one having seen some of the prices.

By security engineer, can we assume you mean alarm (and peripheral) installation?

It may sound a silly question, however, did you use Cat5e/Cat6 cable? - I have seen an alarm tech use 8 core alarm cable!

Secondly, what pinout did you use? What colour on what p? Which standard? and did you check the pin numbering on te IDCs? They are NOT always a straight 1-4 & 5-6. I did some Knone ones which which go 2,1,3,5,4,6,8,7 and they were replacing a different brand which were 6,3,2,1,7,8,5,4

If your tester is just performing a basic continuity test then it wouldn't pick up a split pair which would cause issues. What colour wires have you used for each connection on the punch down terminals of the RJ-45 sockets?