Correction
Pins 1&2 are Transmit and Pins 3&6 are Recieve on a non-crossed port (NICs
& Routers)
Pins 1&2 are Recieve and Pins 3&6 are Transmit on a crossed port (HUBs &
Switches)
""Randy Blumhoff"" <[EMAIL PROTECTED]> wrote in message
908lhc$7k9$[EMAIL PROTECTED]">news:908lhc$7k9$[EMAIL PROTECTED]...
> the simple facts are as follows:
>
> 1) Deciding on a crossover or straight-through cable is a physical layer
> problem
>
> 2) Depending on which cable you use will depend on how the manufacturer
> designed and wired the physical port on each end.
>
> 3) ever situation is different, the only reason you rule works most of the
> time is that manufacturers try to wire their ports to what will be pluging
> into them the majority of the time.
>
> 4) you have 2 pairs of wire - pins 1,2,3,6 (Pins 1&2 - Recieve) (Pins 3&6
> are transmit)
>
> No matter what you are connecting, the recieve must go to the transmit and
> and on the other end the transmit must go the recieve (hence the name
> crossover)
>
> 5) On hubs & switches most manufactures hardwire the the ports already
> crossed, so you don't have to use a crossover cable on a connection to a
PC
> or Router (routers & NIC's are not hardwired crossed), but you do have to
> use a crossover cable on a hub to hub connection because the ports on each
> end are crossed (2 cross ports equals the transmit to transmit and recieve
> to recieve on a straight-through cable).
>
> 6) the MDI/MDI-X switch is used to uncross a port on the HUB - this should
> had work for you (you only set one side to MDI) unless you had a cable
> problem also. (Link lights do not mean the cable is good.)
>
> I hope this helps you the next time you have a problem.
>
> Randy
>
> ""Bradley J. Wilson"" <[EMAIL PROTECTED]> wrote in message
> 00af01c05b92$825a9060$ca01010a@bwilson">news:00af01c05b92$825a9060$ca01010a@bwilson...
> > Okay gang, I had an interesting and annoying situation yesterday
morning,
> > and I'd like to see if anyone else has had an experience like this:
> >
> > My client was installing an older BayStack 301 switch into their
existing
> > network, which consisted of a Bay Access Node router, as well as four
> > stacked SynOptics LattisHubs. The router was experiencing excessive
> > collisions, hence the installation of the switch. So we installed the
> > switch and cabled the router to it, moved all the "power users" directly
> > onto the switch, and left the other users attached to the hub. We
> attached
> > the hub to the switch via a straight-through cable.
> >
> > The users who were directly connected to the switch had no problem
> accessing
> > the network and Internet. The users on the hub were dead in the water.
> We
> > tried swapping out the cable between the hub and switch, tried plugging
> > either end into different ports, tried flipping the MDI/MDI-X switch,
and
> > nothing worked. The only thing that *did* work was using a *crossover*
> > cable between the hub and the switch.
> >
> > Now, the rule (which I gleaned from this newsgroup, btw) is that when
> you're
> > connecting devices at different OSI layers, you use a straight-through -
> > e.g. PC to hub, PC to switch, switch to router, hub to switch - that's
all
> > straight-through. You use a crossover when you're connecting devices at
> the
> > same OSI layer - router to router, switch to switch, hub to hub, PC to
PC.
> > In the situation yesterday, a straight-through seemed logical, as we
were
> > trying to connect a hub to a switch. Am I wrong here? Why did the
> > crossover work?
> >
> > Thanks,
> >
> > BJ
> >
> > P.S. sorry for the Bay-centric example...I'm trying to get them to
change
> > that. ;-)
> >
> >
> >
> >
> > _________________________________
> > FAQ, list archives, and subscription info:
> http://www.groupstudy.com/list/cisco.html
> > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
> >
>
>
> _________________________________
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