Hi, And thanks to both people who have answered my question! Accounting for national/international traffic using the "ipt_account" module seems quite straightforward now. However, since the list of national IP ranges is quite long, it might introduce a serious performance penalty. In that respect, the "dscp" module seems to be a better option -- if supported by my ISP. (It also has the advantage that the classification is always up-to-date with the list of national IP ranges). Anyway, looking at the long list of IP ranges, it occurred to me that this is essentially a decision tree problem, which could be optimised using known algorithms. My googling has returned empty-handed, so my question is: does someone know of any project which aims at optimising iptables rules based on decision trees? If not, I would gladly take a look at the problem when I find some time. Cheers, Jean __________________________________ Do you Yahoo!? Yahoo! Mail - now with 250MB free storage. Learn more. http://info.mail.yahoo.com/mail_250