how to prevent a user from downloading on lan

hi all,

i want to prevent users downloading files in the office as bandwidth becomes very low
and affects work.

one of my friend tried to close the connection using ethercap but this does not work.
i have a debian desktop while other users use MS W!ndows.

Please provide any help. Thanks

what is your internet gateway server ?

You could set up a proxy like squid for example. It has features that might be helping you:
http://en.wikipedia.org/wiki/Squid_\(software\)

you mean the firewall ??
its a cisco firewall.

---------- Post updated at 05:48 PM ---------- Previous update was at 05:45 PM ----------

i already have this on my server.
but i have deactivated

consumes lots of resources.
suggest me something else.

If it consumes lots of resources it's been tuned to consume lots of resources. This is configurable.

You can use group police to create a Software restriction Zone rule which will make it impossible to install any software from the Internet ZOne. This means you can still allow users to download approved programs from an intranet site, but anything on the internet will be blocked. Another option is to set the software restriction rule based on file type. This way you could block *.exe files.