I am in charge of a network of which a portion of it looks like this: One DLink DGS-1210-24 (1) as the main switch. One DLink DGS-1210-16 (2) connected with cat5e 250 feet away connected on (1) One DLink DGS-1210-16 (3) connected with fiber 500 feet away connected on (2) One trendnet 8-port gig switch (4) connected with cat5e 50 feet away connected on (1)
(2) and (3) are connected with multimode fiber and I have 1 miniGBIC on each switch (model DEM-311GT).
I plug in a laptop on (1) and start iperf, then I connect another laptop on (2) and run iperf and get 50 Mbits
When I plug in the laptops on (2) and (3) and run iperf, I get 50Mbits.
I run iperf on 2 servers plugged in on the same switch (1) and I get 1 Gbit
If I run iperf on a computer that is plugged in on (4) and the server on (1) I get 97 Mbits
Can anyone suggest something to try and figure out why there is such a big drop in throughput?