Crossover cable VS straight cable: n00b question

[zveruga]

I finally got my DSL hookup, and I am now configuring my router to work within my home network. I connected my main computer to the router using a cat5 cable, and I was able to browse the internet!

But... I connected my laptop to the router using a crossover cable, and I cant ping the router from my laptop. Am I using the wrong cable?? My understanding was that a crossover is just like a straight except it allows 2 computers to communicate directly... was I wrong???

Please help, before I go out and by different cable...

 

[nightowl]

To connect to your router you need a straight through cable. A crossover cable is only used between 2 like devices (ie: 2 computers or 2 switches, etc). Now, some switches (including the ones built into some SOHO routers) automatically compensate for the use of a crossover or straight through cable when they are used. In your case, it appears that the switch in your router does not do this and you will need to use a straight through cable.

 

[bsr]

ditto

 

[Muse]

Straight through cable? Is this a cat5 or cat5e (or even cat6?) 8 wire cable where each of the successive connectors on an RJ45 plug (1 through 8) connects to the same connector on the plug at the other end?

Does a crossover cable have less wires? If not, what is the difference in the wiring? Will a straight through cable always work instead of a crossover cable when a crossover cable is sufficient?

 

[bsr]

no, straight through is what you would call a patch cable. And crossover is for hooking 2 computers/devices directly to each other, the cable is the same but the internal wiring is different.

 

[Need4Speed]

its called cross over for a reason, because the TX and RX lines are crossed at one end of the cable. lets say you are hooking up two computers without switch, nic to nic:

With a straight patch cable it would look like this
Comp1 Comp2
Rx--------------Rx
Tx--------------Tx

Obviously this wouldnt work since the Rx lines are tied together and so are the Tx lines....however using a cross overcable would give this

Comp1 Comp2
Rx--------------Tx
Tx--------------Rx

Now the Rx of Comp 1 is tied to the Tx of Comp2 and vice versa. Switches and such often take care of this internally

 

[Muse]

OK, I'm still not clear on Straight Cable. Does this have all 8 wires of a cat5 cable match at both ends - blue to blue, striped blue to striped blue, etc.? That is to say, the second position contact in the RJ45 plugs connect to one another, etc. etc.?

 

[bsr]

of course there still the same color on both ends they dont magically change colors, but the pins location on both ends are different.

 

[Muse]

Originally posted by: bsr
of course there still the same color on both ends they dont magically change colors, but the pins location on both ends are different.

OK, you are saying that it does NOT go like this for Straight Cable:

1 <------------------------> 1
2 <------------------------> 2
3 <------------------------> 3
4 <------------------------> 4
5 <------------------------> 5
6 <------------------------> 6
7 <------------------------> 7
8 <------------------------> 8

Well, how does it go?

 

[bsr]

oh sorry, I miss read thought you were referring to a crossover. Yeah thats how it is..

 

[JackMDS]

On Ethernet Network Cables.

AnandTech - FAQ. CAT5 Straight, Crossover. What is CAT5, which one should I Use?

 

[Muse]

Originally posted by: JackMDS
On Ethernet Network Cables.

AnandTech - FAQ. CAT5 Straight, Crossover. What is CAT5, which one should I Use?

 

[JackMDS]

Thanks Muse corrected the link above. Missing [