When to use a crossover cable from Modem to router ??

[joshg]

Hey gang, got a question for ya's..

I am expecting to receive my D-Link DI-704 router/switch pretty soon.. I notice that on the website it says if you can't get an active WAN connection then a possible solution is that you need to use a crossover cable instead of a standard one. Anyway, the question is, what circumstances would call for the use of a crossover cable?

The current setup at this location is 1 Efficient Networks DSL modem with a straight Cat5 cable plugged directly into the NIC of the PC. Now, if I toss the router/switch in the combo, would I need to use a crossover cable instead? Or, since this setup is already using a straight cable to go from the modem to the PC, shouldn't it be fine going from the modem to the router with a straight cable? I mean, isn't it the same type of connection?

Someone please fill me in.. if I need to get a crossover cable then someone please let me know! Thanks!

 

[Mucman]

Straight through should work just fine. That is what I have in my setup.

Not sure why you would ever need a crossover cable...

 

[jfunk]

The only thing I could think of is if the modem had the crossover built into the port, which I have no idea why it would.


I wouldn't worry about it....the straight through will work...


j

 

[damocles]

You would use a crossover if you were running to a hub that didn't have an uplink port

 

[joshg]

ahh ok.. so the WAN port on this Dlink router/switch I'm guessing doesn't require a crossover... thanks for the input guys!

 

[JackMDS]

Unfortunately, Cable/DSL Modem output is not standard.

The majority use Straight CAT5.
You have to use the original cable, or do a little trial and error.

 

[joshg]

yeah Jack that is kind of what I was afraid of.. I do notice that they stated that if you can't connect to the WAN then try to use a crossover cable.. but also on their website in the FAQ section they say you are supposed to use whatever cable was supplied with your modem if you received one. The cable with this modem was a straight through Cat5 (though it was all bent up, I replaced it with one that I made.. ahh much better ) so I am thinking that it should work..

ehh well all parts ordered, including a 75' cat5 patch cable (ran out of my spool.. oh well $8 is cheap )

I'll let you all know of the outcome

 

[Kadarin]

<< Anyway, the question is, what circumstances would call for the use of a crossover cable? >>



If a known good standard "straight-through" cable doesn't produce a link light when both ends of the connection are powered on, try a crossover one. Simple as that.

-j

 

[jmitchell]

one common use of a crossover cable would be when connecting pc-to-pc, without a hub. Both nics would be attempting to transmit on the same wires (i forget which pins) so the crossover switches the transmitting/receiving wires. The only reason you would need a crossover cable would be if the pin layout was switched on the ethernet/WAN port of the router/switch, to a normal pin layout. Does that make sense? If a 'normal' pin layout has the green wire one of the 'transmit' wires, then with a straight through cable, from pc to pc, both nics would be trying to transmit on the same (green) wire, necessitating the use of the crossover cable. A normal pin layout on a port of a hub/switch would already have the pins switched, which is why you do not need a crossover cable for these types of connections. So, the only instance in which you would absolutely HAVE to use the original cable, would be where the evil dsl modem/router company wires their ethernet port with some weird pin layout that was not standard.....:Q