[ask] IP/MAC filters software or mechanism on Linux/FreeBSD?

[Codex Chen]

Hi all,

        Does there exist any software that could achieve such
        a filtering:

        I maintain a MAC vs. IP tables, e.g.

                172.20.100.1    08:00:20:B1:7D:69
                172.20.100.2    08:00:20:B1:7D:58
                ...

        and have a filtering program looking after this table
        to decide if the packets though the Linux/FreeBSD could
        pass or not. Even the MACs of NICs are in the table,
        but if the corresponding IPs are not as listed on the
        table, the packets may not pass.

        It seems there exists no commercial network product
        doing such a thing. I wonder if there is any software
        running on Linux/BSD could achieve this.

        Thanks and with regards,
-- 
Codex Chen(Big5:���w��)
[EMAIL PROTECTED]