s_fawcett
asked on
slow file download from new 3com switch
We have replace some older planet switches with newer 4200 series 3com switches. There are 250 workstations and 24 switches roughly half 3 com half planet switches.
when downloading a 50MB file from the server it takes 10 seconds from a planet switch and 100 seconds from a 3 com switch.
All connections are full duplex and 100Mb as far as I know.
Could there be bandwith throttling or something on the new switches that the old switches don't have?
when downloading a 50MB file from the server it takes 10 seconds from a planet switch and 100 seconds from a 3 com switch.
All connections are full duplex and 100Mb as far as I know.
Could there be bandwith throttling or something on the new switches that the old switches don't have?
It should not take 100 seconds on 3COM 4200, can you see their configuration ? Is it showing connection at 100 Mbit/sec full duplex (check port LED on the switch) ? Try to connect 2 PC's on the new switches and measure download speed ...
How many switches between the server and the workstation? There may be no problem with your switches - they *could* just be deployed in a piss-poor manner. Don't forget if you are daisychainging switches your bandwidth is aggregate: the slowest link determines the highest speed.
ASKER
from server to 1Gb switch 3com 3812. output 80Mb/s
Igb fibre link to planet switch output (100Mb ports) measured at 80 Mb/s
IGb copper link to the 4200 series 3com output (100Mb ports) briefly at 80 Mb but falls to a steady 5Mb/s.
This is using a speed check utility on a laptop (100Mb card) which is used at various points in the server room.
In short not more than 2 switches away from the server.
Igb fibre link to planet switch output (100Mb ports) measured at 80 Mb/s
IGb copper link to the 4200 series 3com output (100Mb ports) briefly at 80 Mb but falls to a steady 5Mb/s.
This is using a speed check utility on a laptop (100Mb card) which is used at various points in the server room.
In short not more than 2 switches away from the server.
hrm, so based on what you said above, linearly the layout is:
[server]---[3com 3812]---[planet switch]---[3com 4200]---[workstation]
If all your switches are managed, I would query the stp configuration. Unless you are specifying your root bridge, you may be passing packets to the edge of your switch fabric rather than taking a direct path. This is only one suggestion.
I would also try spanning the port on the 4200 where you drop to 5Mb/s, and placing a sniffer (Ethereal) on that port.
[server]---[3com 3812]---[planet switch]---[3com 4200]---[workstation]
If all your switches are managed, I would query the stp configuration. Unless you are specifying your root bridge, you may be passing packets to the edge of your switch fabric rather than taking a direct path. This is only one suggestion.
I would also try spanning the port on the 4200 where you drop to 5Mb/s, and placing a sniffer (Ethereal) on that port.
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