> Is it possible to acheive this task on firewall running iptables and > iproute2 (CentOS 4.5) ? > > If so, How can I do such thing? > > If I do such thing, what will happen to the people behind LAN1 ? Will > they get whole 256 kbits/s as before or will they get 256 kbit/s - 64 > kbit/s for their internet access? Yes. use firewall marks and tc. http://lartc.org/