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# -*- shell-script -*-
#
# Ferm example script
#
# Firewall configuration for a web and SMTP server.
#
# Author: Max Kellermann <max@duempel.org>
#
@def $NET_TRUSTED = 195.135.144.144/28;
table filter {
chain INPUT {
policy DROP;
# connection tracking
mod state state INVALID DROP;
mod state state (ESTABLISHED RELATED) ACCEPT;
# allow local connections
interface lo ACCEPT;
# respond to ping
proto icmp icmp-type echo-request ACCEPT;
# remote administration from the company network
saddr $NET_TRUSTED proto tcp dport ssh ACCEPT;
# our services to the world
proto tcp dport (http https smtp) ACCEPT;
# the rest is dropped by the above policy
}
# outgoing connections are not limited
chain OUTPUT policy ACCEPT;
# this is not a router
chain FORWARD policy DROP;
}
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