Layer 2 Cat 5 cables for sale.
All MAC addresses configured identical (to make addressing system easy).
Anyone interested?
In defence of the people who brought DTE and DCE into the argument:
It was an analogy, a memory aid for the old folks amongst us. Works for me
(and if I remember rightly, Chuck the elder), so if it confuses or annoys,
please forget it.
By the way, the layer 2 cables have been withdrawn until further development
can be carried out. Seems to be some problem with them.
Regards,
Gaz
"John Neiberger" <[EMAIL PROTECTED]> wrote in message
4179447.976255551441.JavaMail.imail@puffer">news:4179447.976255551441.JavaMail.imail@puffer...
> There is no DTE or DCE in Ethernet-world. Those are serial communication
> terms that do not apply here.
>
> And hubs are definitely layer one devices, not layer two. To be
considered
> layer two, they would have to be aware of layer two addressing schemes,
> which they are not. They are, however, very aware of the physical
> necessities of ethernet communication on a 10 Mbps/Half duplex LAN, and
they
> do just a bang up job at it.
> Regardless, there's no topological difference between a 10baseT LAN
> connected to a single hub, and 10base5 LAN devices connected to a single,
> long cable. And I hope no one will try to make the case that the cable is
a
> layer two device.
>
> In Ethernet, your transmit pair must connect to the receiver's receive
pair.
> Hub and switch ports are wired internally to be crossover ports, or MDI-X,
> so that any ethernet hosts connected to it will have their transmit pair
> connected to everyone else's receive pair.
>
> This means that if you connect a hub to a hub, a hub to a switch, or a
> switch to a switch using a straight cable you are connecting two ports
that
> are both crossed-over. This will connect the transmit pair of the first
> device to the transmit pair of the second, and consequently the receive
> pairs will also be connected. This obviously will not work! That is why
if
> one of these devices is a hub with an MDI/MDI-X switch, you would set it
to
> MDI to undo the internal crossover. This matches up the pairs correctly
and
> communication will proceed.
>
> If you have two switches, then you have no MDI/MDI-X button to press and a
> crossover cable is required to match up the transmit and receive pairs
> correctly.
>
> I hope that makes sense. As usual, I need to go to bed and get some rest.
> I tend to ramble when I'm sleepy...
>
> Zzzzzzzzzzzzzzzz,
> John
>
> > DTE to DTE uses cross-over cables.
> > Is this correct?
> >
> >
> > ""Bradley J. Wilson"" <[EMAIL PROTECTED]> wrote in message
> > 031901c0608a$b9d87d20$ca01010a@bwilson">news:031901c0608a$b9d87d20$ca01010a@bwilson...
> > > Okay...I've been digesting the responses I've received about this
> issue,
> > and
> > > what I've come up with can be reduced to two comments:
> > >
> > > 1) The fact that flipping the MDI/MDI-X switch didn't initially work
> leads
> > > me to believe that I wasn't using it right. The fact remains that
> > > connecting a hub to a switch must be accomplished using a crossover
> cable.
> > >
> > > 2) Why is that? It's true that connecting devices at different
layers
> of
> > > the OSI model requires a straight-through cable, and that connecting
> > devices
> > > at the same layer requires a crossover cable. So isn't it true that
> > > switches are layer 2, and hubs are layer 1? No. Hubs are actually
> layer
> > 2
> > > devices, and here's why: while a hub may not understand or care about
> > source
> > > and destination MAC addresses, checksums, or what's in the "type"
> field,
> > it
> > > *does* know the rules of CSMACD communication, and has to play by the
> same
> > > rules as other layer 2 devices. Therefore, hubs can be considered
> Layer 2
> > > devices, and thus must be connected to switches with a crossover
cable.
> > >
> > > Anyone see anything wrong with my synopsis above? Let me know. Just
> be
> > > careful with your caps lock key. ;-)
> > >
> > > Thanks,
> > >
> > > BJ
> > >
> > >
> > >
> > >
> > > _________________________________
> > > FAQ, list archives, and subscription info:
> > http://www.groupstudy.com/list/cisco.html
> > > Report misconduct and Nondisclosure violations to
[EMAIL PROTECTED]
> > >
> >
> >
> > _________________________________
> > FAQ, list archives, and subscription info:
> http://www.groupstudy.com/list/cisco.html
> > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>
>
>
>
>
> _______________________________________________________
> Tired of slow Internet? Get @Home Broadband Internet
> http://www.home.com/xinbox/signup.html
>
> _________________________________
> FAQ, list archives, and subscription info:
http://www.groupstudy.com/list/cisco.html
> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>
_________________________________
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
