Uh, shouldn't this be impossible or did I miss something over the years?

[Nebben]

Okay, are these statements true?:

1. If you connect one NIC in a PC directly to another NIC in another PC, you MUST use a crossover cable, not a standard Cat5 cable.

2. If you connect two PCs directly using a standard cable, it will not work.

3. You cannot use a crossover cable to connect a PC to a switch/hub/router.


Because I have always thought, yeah, no brainer, that's how it works -- but then my friend plugged his crossover cable into our switch at a LAN party recently and it worked fine. I was not the only person confused by this, either..

Also, I bought a 100' Cat5e cable to run across my apartment, planning to put a switch at one end.. but I tried connecting it directly from PC to PC and it worked fine.

WTF?

 

[spidey07]

some switches and NICs will "auto-crossover" when connecting MDI-MDI and MDI-X to MDI-X device.

So yeah a crossover cable isn't necessary. always good to assume that the don't however.

 

[skyking]

gigabit nics are auto mdi/mdi-x.
If both are gigabit, any good cable will do.

 

[Nebben]

I see.

Is there any kind of performance difference if you let the NICs self-correct? I have a crappy 4-port hub I could use between the two PCs but if there's no difference I'd prefer to leave it in the storage closet

I'm planning on getting some decent networking equipment soon anyway, though.

 

[skyking]

no performance hit. Either it works, or not.

 

[InlineFive]

Originally posted by: skyking
no performance hit. Either it works, or not.

Well, in some instances using the wrong kind of cable will burn out both sides at a minimum.

 

[Nebben]

I'm using my onboard Marvell connection on my board, and it has auto MDI/MDI-X. It's been working fine. Any cause to worry? I'd prefer not to have my computers light on fire.

 

[skyking]

The "burn out both sides" thing would happen on a non functional connection. Like I posted before, if it works, it works.