Basic firewall rules can effectively act as what you think a NAT does.

The installation changes the system configuration (possibly) by installing services, changing firewall rules, installing new .

Did you accidentally insert a firewall rule that drops all incoming traffic?

Firestarter provides a graphical interface for configuring firewall rules and settings.

AlgoSec BusinessFlow: automatically translates business application connectivity needs into necessary firewall rules.

IP tunneling often bypasses simple firewall rules transparently since the specific nature and addressing of the original datagrams are hidden.

LEO: I suspect he, like I have, has a cheap old router that doesn't do the firewall rules.

When a port knock is successfully used to open a port, the firewall rules are generally only opened to the IP address that supplied the correct knock.

This could add firewall rules to open ports or do anything else that was possible in a shell script.

Security - TCP/IP security groups share a common set of firewall rules.