Hi,
Sorry if my comments hurt heads. I am trying to make the point you need to have a
talker speaking to a listener. This is true of any form of communications. The cross
over simply achieves this. There is no more to it.
Teunis
On Wednesday, January 17, 2001 at 11:12:49 PM, J Roysdon wrote:
> Ouch, you hurt my head reading that. To me, the easier way to explain it is
> that hub/switch ports are crossed, unless specified otherwise (like with a
> toggle port, or a straight-through port). Therefore, to go from a crossed
> hub/switch port to a crossed hub/switch port, you must add another crossover
> to "uncross" one of the two crossed ports. If you want to go from node to
> node, you must add the cross with a crossover. What's the cross doing?
> Nothing more than flipping the transmit and receive pairs.
>
> --
> Jason Roysdon, CCNP+Security/CCDP, MCSE, CNA, Network+, A+
> List email: [EMAIL PROTECTED]
> Homepage: http://jason.artoo.net/
> Cisco resources: http://r2cisco.artoo.net/
>
>
> ""Tony van Ree"" <[EMAIL PROTECTED]> wrote in message
> [EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > Hi,
> >
> > NO!!!!
> >
> > For a start the cable is a layer 1 device as are the electrical properties
> of the ports so the theory of different layered devices does not hold up.
> >
> > Secondly a layer 2 device cannot talk directly to a layer 3 in another
> machine. Layer 2 can only talk to layers 1 & 3 in the device it is in.
> Then layer 1 passes the data (electrical pulses) to the layer 1 on the next
> device. If the layer 2 passes the data (a frame) to layer 3 then layer 3
> decides on where to pass it up the protocol stack only if the layer 3 sees
> it as valid.
> >
> > BASIC COMMS (similar to a normal conversation between 2 people)
> >
> > A talker speaks to a listener via some medium (air, telephone wire, sign
> language) a protocol must be agreed to. Maybe English, Chinese or sign
> language. If someone spoke to me in sign language thay may as well speak to
> me in Chinese as I don't understand either nor would sign language be
> appropriate over a phone.
> >
> > Each talker must have a listener if you have two devices that are the same
> thier electrical paths will be the same therefore you need a crossover.
> Switch to switch (both layer 2 SO WHAT), Switch to Hub (Layer 2 to Layer 1)
> both are similar electrically in there port design (this was deliberate to
> make connections to PC NIC's and routers etc simple else would would need a
> NIC for a Hub and a different one for a Switch) A switch to a hub requires a
> crossover.
> >
> > A router or PC to a switch or hub. The ports are different electrically a
> straight cable will work. A router to a PC are similar electrically these
> need a crossover.
> >
> > X cross over simply puts the send signal to a receive on similar port
> types nothing more flash than that. The secrete is cables are a part of
> layer 1 and have nothing to do with the upper layers.
> >
> > I put a spread on this and the pinouts a couple of weeks ago.
> >
> > Hope this makes it easier.
> >
> > Teunis
> > Hobart, Tasmania
> > Australia
> >
> >
> > On Wednesday, January 17, 2001 at 10:55:58 AM, Lowell Sharrah wrote:
> >
> > > funny,, I said the same thing over two months ago. Good rule to follow.
> > >
> > > >>> Sampy Ren <[EMAIL PROTECTED]> 01/17/01 10:34AM >>>
> > > The rule to follow about cross-over or straight
> > > cabling confusion is this :
> > >
> > > If you are connecting same layer devices, use a
> > > cross-over cable (as in switch to a switch-layer 2 to
> > > layer 2 or a router to a router -layer 3 to layer 3).
> > >
> > > If you are connecting devices from different layers,
> > > use a straight cable ( as in connecting a switch to a
> > > router - layer 2 to layer 3 connectivity).
> > >
> > > Hopefully this gives you the concept of the cabling
> > > schema.
> > >
> > > Regards/Sampath.
> > >
> > > --- Chuck Larrieu <[EMAIL PROTECTED]> wrote:
> > > > Didn't we just have this discussion - straight thru
> > > > or crossover - a couple
> > > > of weeks ago?
> > > >
> > > > -----Original Message-----
> > > > From: [EMAIL PROTECTED]
> > > > [mailto:[EMAIL PROTECTED]] On Behalf Of
> > > > Yonkerbonk
> > > > Sent: Thursday, December 28, 2000 12:47 AM
> > > > To: sean; [EMAIL PROTECTED]
> > > > Subject: Re: crossover or straight cable?
> > > >
> > > > A trunk port is simply a port that has traffic from
> > > > more than one VLAN running over it. It is a function
> > > > of the software to combine and split the data. That
> > > > has nothing to do with how the cabling is done.
> > > > If you have a trunk running from switch to switch,
> > > > it
> > > > will be crossover. If you have a trunk running from
> > > > switch to router, it will be straight through.
> > > > Normal
> > > > cabling scheme.
> > > >
> > > > --- sean <[EMAIL PROTECTED]> wrote:
> > > > > Tony,
> > > > >
> > > > > Are you saying that, to connect "trunk" ports
> > > > > between switches, crossover
> > > > > cable is required?
> > > > >
> > > > > I know for "switch" ports that's the case, I am
> > > > > wondering if it is true for
> > > > > trunk as well.
> > > > >
> > > > > Tks
> > > > >
> > > > >
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