I am trying to connect two devices one of which is only capable of 10Mbps and does not support auto-negotiation. (The other is a black box, I am unsure how to tell whether it supports auto-negotiation, although it works when connected to my PC at both 10/100Mbps)
I can connect these devices using a switch, and they talk quite happily. However if I connect the devices directly to each other then no packets seem to traverse the link. I have tried four cables, a straight-through, a cross-over, a straight-through with TX+ and TX- wires swapped, and a cross-over with TX+ and TX- wires swapped. I have tried the latter two cables both ways around. (This is in case pins 3 and 6 are swapped in either device, I read that this can be a problem with 10M which uses polarized transmission).
I can connect to either device from my PC if I limit my NIC to 10M and ask it not to auto-negotiate.
Is there something else that the switch could be doing to make this connection work? Are there any other things I could try to get a cable between these devices?
Best Answer
Have a look at the Wikipedia article.
The switch may correct a duplex mismatch. Maybe you can switch the non-blackbox between half and full duplex?