Firewall Settings
RHEL 6
RHEL 6 uses iptables by default to configure its firewall settings. These
can be updated using the /etc/sysconfig/iptables file, or, if you have
X Server running, there is also a GUI for editing the firewall that can be run
using the command:
system-config-firewall
RHEL 7
RHEL 7 continues to use iptables under the hood, but the preferred way
to interact with iptables was updated to using the firewall-cmd
command or firewall-config GUI. For example, the following commands
will open up port 8082 publicly:
firewall-cmd --zone=public --add-port=8082/tcp --permanent firewall-cmd --reload
Debian 9.x
Debian Stretch uses iptables by default to configure its firewall settings.
These can be updated using the /etc/sysconfig/iptables file, or you can
use the iptables command:
sudo iptables -A INPUT -p tcp --dport 8181 -j ACCEPT sudo iptables-save
Ubuntu 16
Ubuntu 16 comes with a ufw (Uncomplicated FireWall) command, which
controls the firewall, for example:
sudo ufw allow 8181
