iMac, SHub2ac & gigabit ethernet
 

I've just been upgraded to 200mbps and sent a Superhub 2ac unit which has 4 gigabit internet ports.

I run a late 2010 iMac 21" which is also capable of gigabit ethernet, I have a 12ft Cat5e cable between the units.

The Mac network card is autodetecting at 100base t an connecting ok. If I manually 'force' the card to 1000base t I get the dreaded 'Cable unplugged' alert.

I can get ~200mbps over 5.0ghz WiFi so Shub is capable of the spec speed.

Any idea why the ethernet card is not detecting the gigabit ports? Is the fault with the Mac or the Shub?

Cheers.

Re: iMac, SHub2ac & gigabit ethernet
 

Tried a different slot on the shub?

Re: iMac, SHub2ac & gigabit ethernet
 

Yup... all of them :)

Re: iMac, SHub2ac & gigabit ethernet
 

... and a different Cat 5e cable?

What colour is the LED at the back of the SH? Green or Orange?

Re: iMac, SHub2ac & gigabit ethernet
 

If you put both ends into the same hub and it flashes orange your cable is faulty or not 5e

Re: iMac, SHub2ac & gigabit ethernet
 

No same cable, but works on 100base t.

Yellow.

---------- Post added at 16:14 ---------- Previous post was at 16:12 ----------

Difficult to put both ends in at present. (is that wise -never heard of this test before)

Run is under floorboards. Will have to source another cable

Re: iMac, SHub2ac & gigabit ethernet
 

That's the point of changing the cable. If it is supposed to run at 1 Gig subject to supply data rate (i.e. LED is green) but doesn't then it might be faulty. It would quite likely run at 100 meg as you've proved.

It decides the rate based on Autonegotiation described at https://en.wikipedia.org/wiki/Autonegotiation

Re: iMac, SHub2ac & gigabit ethernet
 

OK, good point, I'll source a Cat6 cable and try it.

Cheers

Re: iMac, SHub2ac & gigabit ethernet
 

Don't try cat 6 just yet. 1Gb/s Ethernet requires all four pairs of wires to be connected. If you have a fault in just one pair you will only get 100mb/s.

Is this cable a pre-assembled unit (including connectors) or did they get crimped onto a length of cat5e?

Ian

Re: iMac, SHub2ac & gigabit ethernet
 

Probably a faulty cable as Eeeps said.

Re: iMac, SHub2ac & gigabit ethernet
 

@Eeeps: Not really sure it may have been one I made up. Been that long, when I think of all the cables I've given away over the years... :)

I may as well get another, have a mate that still does some IT I'll beg one off him. :)

Re: iMac, SHub2ac & gigabit ethernet
 

Ok, cable was the problem! Yippee! :)

Managed to borrow a Cat5e and card auto-detected 1000base t.

Thanks for all tips and pointers.

Re: iMac, SHub2ac & gigabit ethernet
 

Pleased to have been of assistance!