Packet Tracer: Router to Switch, why crossover?

Why is it that I have to use a cross-over cable to connect a router and switch in packet tracer? I've always known it to be done with a straight-through, but that doesn't work and even automatic cabling uses crossover, why?

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Comments

fivedollarcouch

just verified auto cable chose a straight through for me from switch to router, and correctly did a crossover for switch to switch. not sure what would cause yours not to

fadhil

the concept behind:
straight through is used to connect the different devices eg router and switch or computer and switch
crossover is used to connect the devices like router and router ,switch and switch or router and computer

TehToG

That doesn't fit Fadhil. The concept is that 'like' devices will have the same pin arrangements and so you need a crossover such that both devices transmit and receive connect to their opposite on the other side. Connecting a router and a Switch should use a straight through cable.

iamme4eva

I've never found that on packet tracer.

The "like" devices rule has the obvious exception of PC - Router - they have the same pinouts so need a crossover.

FWIW, I think I only have one crossover cable in my lab - and it's collecting dust. Most devices are auto-sensing these days.

spiderjericho

iamme4eva wrote: »

FWIW, I think I only have one crossover cable in my lab - and it's collecting dust. Most devices are auto-sensing these days.

This is true. I remember I was configuring a Fortinet Firewall pair and our experienced firewall tech said I had to use crossover and I was like why? Most NICs are auto MDIX. You only run into the cross over issue when dealing with old hardware, but it's still useful and important to know. Sort of like the old 5-4-3 rule despite no one deploying hubs anymore.