Hello,
I have one c2950-24G connected directly (point-to-point) to a c2924MF-XL via a GBIC Gigastack. The versions are 12.1(9)EA1 and 12.0(5)WC3b. The link is all the time flapping: the problem is the negotiation. In this type of connection it should be full-duplex. Both devices are in auto mode, but the c2950 always negotiates to full, and the 2912 sometimes to full, sometimes to half. I have tried to reload, swap and reinsert the gigastack razors, take out the cable and put it again..., but it is difficult to troubleshoot because sometimes work sometimes don't.
If anyone can help it would be nice.
Best regards,
Ruben