jdMorgan - 3:51 pm on May 29, 2009 (gmt 0)

It won't as long as there are no 1 GB/s devices sharing that same physical port on the switch. It is the clock speed used per-port (i.e. on each individual switch port) that is important here.

See the diagram puremetal posted above. The main network is 1GB/s, and one of the ports on the 1GB/s switch goes to a second switch, and everything plugged into that second switch is 100 MB/s. The devices below the second switch communicate at 100 MB/s, but the link from that second switch to the first switch will happily run at 1GB/s. So, it is the second switch that partitions the 1GB/s and 100MB/s segments.

Jim