Is auto-sensing separate for each ports [Archive] - SpeedGuide.net Broadband Community

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pengster
07-31-08, 03:16 PM
Hi

I'm a newbie at networking stuff. Plz bear with me.
I'm trying to understand if auto-sensing affects only the speed of the port or the whole switch?

Ok lemme back track and give background.
My router just fried and I realize that my home network is growing. I want to re-use my old Linksys WRT54G router and splurge on a good gigabit switch. I'm simply preparing for the day when my ISP offer gigabit service at reasonable price.

So I want to buy a 16-port gigabit switch and eventually upgrade all my NICs and router to gigabit. 2 of my comps already have gigabit NICs but the rest are still 10/100. So I know I want auto-sensing ports on the switch I buy but I don't quite understand all the marketing jargons on their shrink-wrapped boxes.

So what do I look for to make sure of the following?
If I plug in both a gigabit device and a 10/100 device onto the switch. The switch will allow both device to use their max speeds independantly, and not revert all ports to the lowest-common speed?

This isn't a problem for the case of 10Mbps vs 100Mbps devices because all modern routers/switches auto-sense independantly on each port . But I'm told gigabit switches aren't always that way - yet.

thanks in advance
pengster

YeOldeStonecat
07-31-08, 03:25 PM
With switches....yes each port is independent. So...say you have a pair of 10 meg NICs and a pair of 100 meg NICs and a pair of giga NICs..in a gigabit port. The gigabit NICs will still work together at gigabit speeds, the 100 megs at 100 speeds, and the 10 megs at 10. The highest speed NICs can feed the backplane at their maximum speed.

pengster
07-31-08, 07:30 PM
hmmm weird,

Then how come the store's tech guy (not the sales guy) actually discouraged me from buying their switch (I believe it was a Linksys) for the reason I just posted here?

Are switches all made the way you described with no exceptions ? and this guy is out of his mind chasing a customer away?
or
could he be thinking I'm looking to buy a router (eventhough I was holding the box in my hands) ?

pengster

YeOldeStonecat
07-31-08, 07:47 PM
hmmm weird,

Then how come the store's tech guy (not the sales guy) actually discouraged me from buying their switch (I believe it was a Linksys) for the reason I just posted here?

He wasn't really an experience tech guy....didn't know what he was talking about? If some computer chain kid tried to tell me that if I plugged a 10 meg NIC into a 24 port 10/100 switch that had 23 other 100 meg NICs plugged into it...it would drop the speed of the entire switch to 10 megs...I'd get on the intercom and laugh out loud at his face so the entire store would have heard it.

pengster
07-31-08, 08:50 PM
lmao

Thats a very vivid imagination. I could just see the store manager grappling to get the the mike out of my hands. Ok, while my coworkers are giving me weird looks for laughing at my LCD.

You gave an example of 10Mbps vs 100Mbps. But can I assume you would also laugh at the tech guy's face if he said the same thing to the case of 100Mbps vs 1000Mbps ?

pengster :D

YeOldeStonecat
08-01-08, 07:49 AM
You gave an example of 10Mbps vs 100Mbps. But can I assume if he said the same thing to the case of 100Mbps vs 1000Mbps ?

pengster :D

:nod: He would be just as wrong. Ports on a switch have their own individual link to the "backplane".