Ive got a gigabyte network switch in my computer room....

and a cable running down into the celler to another swotch...

Im 1/2 way through upgrading everything to gigabyte... but if I remove the old 100mb switch in the cleer and replace it with the gigabyte one... the cable running down from my switch stops working ?

(no lights on at eother end, and cant connect through it)

works fine back in the old 100mb switch again... already re-crimpred the end just incase (shortend the cable by a foot at the same time just incase!)


any ideas anyone ?
(both gagabyte switches are this one..... http://www.tekheads.co.uk/s/product?product=604327 )

Id heve thought if the cable run between the 2 wasnt up to gagabyte it would just connect at 100mb ?

....using the 100bit switch I can transfere through it at a steady 12mb/s... which is the top limit for 100mb anyway right ?... so the cable should be fine for that ?


(p.s. its a ******** to run a new cable!)

cable not upto gigabit specification?
Port doesnt auto sense a normal cable / crossover cable?
Tried recapping the plugs?

Quote from: EggtasticoPort doesnt auto sense a normal cable / crossover cable?

i was gogin to suggest that

Easy to test with this
and a short crossover or stright.

I do not know if cat6 is needed.
 

hmmm.... well it says auto sensine for straight over / crossover on the box :-o

only just realised what I should do.... stick them next to each other with a chort good network cable between them and see what happens !

If its a cross over cable then chances are it is wired up incorrectly.

100MB cross over cables are different to gig ones.

As far as I know, 1000mbit doesnt auto negotiate.
Set the NICs to be 1000mbit/Full Duplex.

This is wrong...1000Mbit should always be autosensing. Gig-E specs provide for a far more reliable auto-detect than 100Base-T, If youre pulling a 10/100 device into a gig switch you may want to hard set both ends but if they are both Gig you should leave them be.

Gig uses all 8 wires IIRC, whereas 100Mb only uses 2 pairs. If theres something up with one of the redundant pairs then the cable could well work at 100 and fail at 1000.

Incidentally, I didnt think there was any such thing as a X-over gigabit cable? Never actually used gig ethernet yet though, just read up on it when cableing my house in the hope that just maybe I wouldnt need to replace the cables to go gigabit. (yeah right, like thats going to work, worth a try though).

Quote from: MongooseGig uses all 8 wires IIRC, whereas 100Mb only uses 2 pairs. If theres something up with one of the redundant pairs then the cable could well work at 100 and fail at 1000.

Incidentally, I didnt think there was any such thing as a X-over gigabit cable? Never actually used gig ethernet yet though, just read up on it when cableing my house in the hope that just maybe I wouldnt need to replace the cables to go gigabit. (yeah right, like thats going to work, worth a try though).

Can one alter a cat5 so one uses all pairs and hence make it a 1000 cable ?
perhaps with a converter at each end ?

CAT5e will support gigabit as long as the pinouts of the  cable are correct. There shouldnt be any need to change/convert an existing CAT5e 10/100 cable.

Although, iirc, there are more stringent distance and interference rules when using 1gig.

dont know the full spec of what Gig Ethernet needs as ive not come across it yet at work (dont get enough new kit, grr, lol)

pretty sure though, that gigabit Ethernet does indeed use all 4 pairs of the cable,
 where as 100mb only uses the orange and green pair i think (going on 568B)