Problem with ppp keeping link up
I have a Debian gateway system, doing pppd demand dialling. ISP gives
a new IP address with each connect. No problems with that - pppd works
My problem is that once up, the link often does not shut down even when
there has been no traffic from me for longer than the set time-out
The reason appears to be traffic coming in from outside. It looks
(Ethereal) as though it is traffic for a previous user of the IP address
I now have.
My (simple) iptables rules ensure that my machine does not respond,
but the traffic is enough to trigger pppd into keeping the connection
I note that back in Jan 2003, someone had the same problem but got no
response on the debian-user mailing list.
How can I ensure that traffic initiated from outside does not keep
the dial-up connection open?