what cable to connect the fa0/0 port on a router to the fa0/0 switch port

[stanislausugbome1]

i don't know if i know this question, but i got it in the exam recently and i chose - straight-through cable. please is this right? if not then what is the right cable to use?

[pkhatri]

That is correct - a straight-through cable is what you need.

Hope that helps - pls rate the post if it does.

Paresh

[ankurbhasin]

Hi Friend,

As Paresh already confirmed you the right answer but I will tell you the trick to remember this.

Divide the major network devices in 2 groups

Group A (Router,PC,Server)

Group B (Switch,Bridge,Hub)

Whenever you have to connect devices in 2 different groups use straight through cable and when you have to connect any devices in same group use corss cable.

HTH, if yes please rate the post.

Ankur

[yasirirfan]

please let me know which router ur using. As far as i know majority of routers work with cross cable.

[ankurbhasin]

Hi Friend,

No router needs a corss cable to connect to switch. They always need a straight cable.

Yes if router has a switch module and you connect via switch module to switch then you need a cross cable.

But talking about a ganeral router with its layer 3 interface when connected to switch need a straight cable for sure.

Regards,

Ankur

[stanislausugbome1]

that is the big problem: in the exam, the question just stated 'what cable would you use to connect the fa0/0 port of a router to the fa0/0 port of a switch?' they did not state on which particular router. so what would your answer be to such an ambiguous question? straight-through or crossover?

[Bobby Thekkekandam]

the numbering "fa0/0" on a router logically precludes a switch module on a router, as it would be something like "fax/y/z" so you can assume a router port connecting to a switch port, which will always be a straight through.

HTH,

Bobby

[stanislausugbome1]

so in effect, the statement below is wrong?:

"The fastEthernet ports on a router and a switch are both RJ-45 ports. It means we have similar devices on both ends. So a crossover cable must be used here."

apparently the above statement is wrong!

[ankurbhasin · Accepted solution]

Hi Friend,

Yes this statement is wrong!!

As I mentioned in my first post divide the networ device in 2 groups.

Switch and Router belong to different group so need a straight through cable and if any device need to be connected in same group needs a cross over cable.

HTH, if yes please rate the post.

Ankur

[Asad habeeb]

It was wrong.

[paul driver]

Hello
Nowadays ports on routers/switches usually support auto-mdix which can negate the need for crossover cabling between devices unless that is you are working with quite old hardware.

[Joseph W. Doherty]

Yes, as noted by Ankur, and others, that statement is wrong.

Although both devices use RJ-45, wiring of pins differ between MDI and MDI-X.  For MDI <> MDI-X you'll need a strait through cable.  For MDI <> MDI or MDI-X to MDI-X, you need a cross over cable.

However, as mentioned by Paul, some devices can dynamically self configure their port as MDI or MDI-X.  For those devices, you can use either cable type.  Also, however, for devices that support auto MDI/MDI-X, the port might need to be configured a certain way, on Cisco devices, usually port must be "auto" mode.  If you hard configure speed/duplex, the port will normally be configured just as MDI or MDI-X, whatever is "normal" for the device.

Lastly, standard MDI or MDI-X for the device is generally set so that for unlike devices, that usually connect, one is MDI and one MDI-X, using, again, a strait through cable, e.g. switch <> host or switch <> router.  "Like" devices, e.g. switch to switch (copper) will have same type of connection, which, without auto MDI, will need cross over cable.