Testing iptables setup

["Richard L. Dery" <dickdery@teleport.com>]

I have the following setup in my /etc/ppp/ip-up.d directory:

(bash script stuff deleted)

## Create chain which blocks new connections, except if coming from inside.
# iptables -N block
# iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT
# iptables -A block -m state --state NEW -i ! ppp0 -j ACCEPT
# iptables -A block -j DROP

## Jump to that chain from INPUT and FORWARD chains.
# iptables -A INPUT -j block
# iptables -A FORWARD -j block

(You may recognize them from the Packet Filtering HOWTO).

When I run iptables -L after connecting these rules are displayed.

Is there a way to test to show that these rules work?


Thank you.

Dick Dery