Can you draw a diagram? If I'm understanding you correctly, are you trying to use 1 cable for 2 separate Ethernet connections? I'll also ask the obvious, why haven't you just replaced the cable?
Right now I still need to fix 1 of 2 broken cables that cable is about 30' feet long and is running between 2 Dlink gigabye switches my other cable which is working now is coming from the middle of my living room/kitchen with my newly moved router/modem so with the new setup my network starts at router/modem goes up to the ceiling and through my bedroom wall and drops down to the first switch and which feed those devices.
Then from that switch I go around room 75 feet and come to to my other switch which feed my devices near my HDTV. those cables I built myself about 10 years ago and have been working fine for the most part.
So cable 2 has been stapled to my baseboard that the one I tried to repair using the normal rj 45 connectors and due to pain I get every day from auto accident that give me pain to my neck, back and headaches I it limiting my ability's a lot these days heres what happened when I could get 2 new connectors to fix the cable which should be 5 min simple job but it has not been.
So I have the above listed network boxes that work using a punch tool so used first 1 then 2 boxes because now while the boxes cant connect to my switches I can use some made patch cable to do the job even though they may be not get the job done at least it be done.
I made my connections using the B wiring setup hooked up the 2 boxes and was easy to do once I had cutter placed properly. So now I hook up the lan tester and I and I know the lan tester show good as showing all the pins and some other pattern on the remote side and after seeing that with everything reconnected to my switches it was not working.
At some point I decided to get rid the faulty boxes and I bought these new pass through rj 45 connectors and just fix re-fix the cable that way.
So after doing the same straight thru B cable I am now showing with my lan tester that the master side of my cable will show a normal 1-8 lights and the remote side has a strange pattern but one thing I cant figure out is why does the tester show good cable.
I posted the facebook video to show that but I think people reading this thread still dont know whats happening and they will probably say fix the end that bad when the tester is reversed that always the side that lights properly and whatever end of the cable that connected to the remote side of the tester is got weird pattern.
The lan tester seems to be simple tool to say was wires are crossed or missing I never had it work like it doing now that way this thread is posted plus why wont the network boxes or my these pass through working either!