Irving_Wolfe@happym.wa.com (02/13/91)
I have two 10baseT repeater-hubs, 3Com MultiConnect boxes with triple twisted pair modules. These modules have internal crossover. When I plug two computers into one hub using straight-through cable, they talk fine. When I take a length of 1-3,2-6 crossover cable and connect the two computers directly, they talk fine. When I plug one computer into each of the repeater-hubs with the tested straight-through cable and connect the two hubs together with the tested cross-over cable, nothing works. The little yellow "received" LEDs flash -- all four of them -- in time with the ping, but only one ping in every 10 or 20 is returned successfully to the originating system. Neither 3Com tech support nor the tech support department of Valinor, the distributor we bought from, has been terribly helpful, except to tell us that we should re-check everything, it's supposed to work. As noted, all the cables work right when used in other configurations. Also, I ran an impedance check on all three cables and we are within spec. All lengths are reasonable -- we are testing close-proximity units and have not tried to take advantage of 3Com's over-spec distance capability or existing phone wiring yet. I have an 8-machine network to put together and we are already far behind schedule. Can anyone help? Hints and hunches would be real welcome at this point, as would solutions, of course. What could we neophytes be overlooking? Thanks for your help!