One PC doesn't connect to internet via new router

[legions91]

Hello.
I've decided to switch my basic ol' tp-link router for something better, so I bought TOTOLINK A3002RU. Configuration went fairly smooth, wi-fi connected immediatly, however there are 3 pc's connected via cable to the router.
First one was working perfectly fine since the beginning.
Second, I had to use a new RJ45 cable, otherwise neither PC, nor router would see each other. It's kinda weird, because tp-link recognizes that pc on the old ethernet cable just fine.
Third one simply doesn't connect to the server. Again, works fine on the old router.
What seems to be a problem? Faulty router? Configuration? Dated ethernet cables?

 

[kanewolf]

First verify that you have the ethernet port set for DHCP for IP and DNS.

 

[legions91]

I do.

 

[kanewolf]

I do.

OK, then post the results of ipconfig /all ...

 

[legions91]

I know that's not what you asked for, but I've decided to go on and buy a RJ45 Cable Tester as most cables are homemade by my father.
Lights light up in that order:
1-1
2-2
3-5
4-4
5-3
6-6
7-7
8-8
So, crossover cables should go 36145278, right? Could it be that the cables are the problem here? If yes, then why does my old router have no problems with either of those cables?

 

[kanewolf]

This is the optimum wiring for ethernet cables TIA5698B -- http://discountlowvoltage.blogspot.com/2009/10/standard-568b-wiring-diagram.html

 

[legions91]

I know, I checked which should be which, but that's not the question. My question is, how are they working when they are clearly wired wrong and why are they working perfectly fine with the old router and the new one won't recognize any of them?

 

[kanewolf]

My guess is the tp-link is 100 Mbit which only requires 4 of the 8 wires. Gigabit requires all 8.

 

[legions91]

Oh, yeah, that would make sense. I'll rewire my cables over the weekend and say if it worked. Thanks.