Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
Community Member

QOS Setup for 3750 - Windows file Server

Hi All,

I have single site with 3x 3750 stacks where around 100 users and one fileserver connected (all using 100Mbps) We have issues where a user might be copying a large file to a file server which effectively slows down all other user access to the fileserver. What will be a best way of implementing QOS so users get equally share of bandwidth?


VIP Purple

HelloAre all your users and


Are all your users and servers in the same vlan? If so this could be a problem as they will be sharing the same broadcast domain.

A solution to this would be to segregate the servers and users into their own vlans (broadcast domains) this then would minimize the traffic flow when a client ( user) is "speaking" to the server



Please don't forget to rate any posts that have been helpful. Thanks.
Community Member

Hi Paul,Thanks for your

Hi Paul,

Thanks for your comment. I can confirm user and server are in diffrent vlan. Issues occurs 
e.g. when user A in vlan 10 on port fa1/10 copies a 10gb file to file server in vlan 20 on port fa1/20.
During the file transfer fa1/20 port is utilized 100% during the file transfer. This mean when a user B on port fa1/11 on vlan 10 tries to access files on the server it is either not repsoding or very slow. All the server port bandwith is used by user A. Is there a way  i can loadbalance bandwith when 2 users connect to file server on port fa1/20 it assigns them 50/50 of the 100Mbps or when 10 users connect 100 divide 10 = 10mb per user?



Super Bronze

DisclaimerThe Author of this


The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.


The 3750's QoS implementation doesn't support an easy method to fairly share bandwidth.  You could police user ports such that when they exceed a certain amount of bandwidth usage to the server, mark those packets so they can be deprioritized on the port to the server.


Another approach to avoid this issue is increase bandwidth to your server.  If any of your 3750s have gig uplink ports, and if your server has a gig interface, you might migrate to gig.  Also if your server has multiple ports, whether FE or gig, you might see if the server supports any kind of port channeling.

CreatePlease to create content