19.3. Allowing and Denying Network Traffic

To restrict the types of connections and packets that your firewall will accept or forward, you need to create additional firewall rules. The best place for these rules is the Packet filtering table, in either the Incoming packets or Forwarded packets chain. If your firewall is acting as a router and you want to protect systems on the secure network that it is attached to but not the firewall itself, the Forwarded packets chain should be used. However, if you want to protect both the firewall and other systems that it routes to, rules should be added to the Incoming packets chain.

It is also possible to restrict data being sent out by your system, which may come from local processes or be forwarded from ...

Get Managing Linux® Systems with Webmin™ System Administration and Module Development now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.