Bypass data limit for a special ip

Hi
I have 2 catagory user that is 2gb or 4 gb download limit.
I also have a local server that stores some software, song and other
to download.
I want to bypass the loacal server so that, the file downloaded from
local server will not be calculated within data limit.
Please help me.

Without your more configuration information it is hard to answer… I would say accept packets to that server based on that IP then PASS-THROUGH=NO on NAT. This will bypass your other rules.