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files copy crossing office LAN is super slow

Level 1
Level 1

Two computers (XP and Win7) connected on office LAN, cisco 2960, not same switches, but all in the same rack, and link togeter, same IP subnet, tried to copy some kind of 26G files from one to another, using Windows share folders, and it showed need 23 hours to finish the copying.

It's not the first time, actually we always experienced very slow speed when copying files on Windows share folders.  Did not see any particualler message on the switch.  ports are all full/100m. 

Any clues or advises where I should start with to address this very annoying issue.

Thanks a lot.

9 Replies 9

Dennis Mink
VIP Alumni
VIP Alumni

What sort of throughput do you get when using FTP to copy the file across?

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Also good to start with small network diagram and configuration of switch ports connecting the switches and connected to PCs.




Please check the switch ports end to end  if have been configured as Full Duplex.

Also check the interfaces of the switch for late collisions, drops etc.

The problem described above is common for switch ports configured as hald duplex

Plz, update with the sh interface x.x output if this does not solve the problem

Hope that helps


switch ports are set auto, but 'show inter status' showed all connected ports are full/100.  Didn't see errors, collisions or drops on 'show interface ...' .

And this issue happened many times, on many different PCs, connecting on many different ports.....:(

OK. I assume that the show interface output also show full-duplex.

did you check the logs, the cpu load during the problem?

No logs showed any outstanding issues on my switches. 

Actually, I experienced this issues for many years, on many different network environments(not all networks I worked before).  Ping tests with payload were all good, show interface out put was good, no valuable logs, most applications ran smoothly, but just copying files via shared folders was always very slow.

I am thinking this should be some common issues, but not a particular case on my current office LAN.  Really want to find out why and get it fixed.


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What the physical topology of these switches?  Also, Minkdennis asked an important question, same issue if you do a copy with FTP?

switch ports are set auto, but 'show inter status' showed all connected ports are full/100.  Didn't see errors, collisions or drops on 'show interface ...' .

Please post the output to the following commands to both switchport ends:

1.  sh interface ; and

2.  sh contr e

VIP Alumni
VIP Alumni

  You say the ports are set as auto , just to verify when you do a "sh int status"  it shoudl look like this   .  If it doesn't have the little "a" in front of full  then it's not auto and is hardcoded . If it's hardcoded and the client nics are set as auto then you have a duplex mismatch which will cause all kinds of errors because the nic will then default to half duplex .  Verify the switchports and the nics are auto for speed and duplex. Although even if mismatched it shouldnt take 23 hours.

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