Hello Expert,

I am having file copy slowness issue in uni-direction.

Scenario is

Site A

System A -IP address 10.3.6.165

Site B

System B -IP address 10.3.210.150

Site A and SiteB are connected through 10G dark fibre and static route is been used to inter connect site A and Site B . For testing purpose I used 1GB file to copy across. Initially I copied from Site A to Site B and it took less than 2mins to copy the file across site B.

I took the same 1GB file and copied across from siteB to SiteA and it took more than 100mins to copy the file. At both the end operation system is windows 2003 with SP2 even I hardcoded the interface speed to 1000 .

I would like to know what causing this slowness and what are things need to be checked to identified the slowness.

Also traceroute from SiteA to SiteB took 4 hops and from SiteB to SiteA 3 hops , but file copy is faster is from SiteA to SiteB and slower from SiteB to SiteA. Whole network is CISCO farm and the switches involved are 6500, 4500, 3750-E and 3750.

Also we have L2 spanned between site A and SiteB and the subnet 10.3.6.0/24 is spanned via the darkfibre and the file copy is quicker within the same subnet spanned across the darkfibre. But the subnet 10.3.210.0/24 on siteB is in different switch to spanned switch.

Please help me with valuable troubleshooting suggestion.