[c-nsp] GigE Link Problem

[Mark Taylor]

Sorry if this does re-post, but I don't think it made the list originally 
due to a problem at my end:

Hi,

I am connecting a 3750-48TS switch to a 2948G switch with Gigabit Ethernet.
The 3750 has a 1000BaseSX SFP port (GLC-SX-MM) and the 2948G has a
1000BaseSX GBIC (WS-G5484). These are connected together with a 3m length of
SC-LC multimode fiber.

I cannot get the link between the two switches to establish. I have tried
reverseing the TX and RX on the SC end of the fiber, using different fiber,
using a different GBIC and using a different SFP.

I have tried "set port negotiation 2/50 enable" on the 2948G which didn't
work. When I turn off this negotiation on the 2948G using "set port
negotiation 2/50 disable" it displays a link light and connected status, but
the 3750 shows a down port. You cannot force the speed or duplex as the
ports have a fixed config of 1000 full.

Does anybody have any ideas why this might be happening and configs which
will make it work?
For reference the 2948G is CatOS and 3750 is IOS.

Thanks in advance,
Mark.