We have some 3560G switches and 2950 switches. There is one 3560G used as a distribution switch connecting to other 3560G switches or 2950 switches. We configured 1000/full between 3560G connections and configured 100/full between 3560G and 2950 switches. And there is no link negotiation issue at all. But the weird thing is I found in the trunk interfaces of 3560G distribution switch to the other 2950 switches keep getting out-discard errors. And correspondingly the trunk interface in 2950 connecting 3560G distribution switch keep getting Rcv-Err. I checked the traffic through these trunk interfaces. Traffic there is very light. Less than 2Mbps. So we are not overusing the bandwidth which is 100Mbps.
The other Giga trunk links between 3560G distribution switch and the other 3560G switches has no error at all. I see chaning the hold queue size is a bad idea. Also I tried set up auto/auto at both ends and trimmed some traffic in the 100Mbps trunk links. Nothing helps. So if you have any experience on this, please help throw some light on this issue. I really appreciate it.