The Salt master communicates with the minions using an AES-encrypted ZeroMQ connection. These communications are done over ports 4505 and 4506, which need to be accessible on the master only. This document outlines suggested firewall rules for allowing these incoming connections to the master.
No firewall configuration needs to be done on Salt minions. These changes refer to the master only.
The lokkit command packaged with some Linux distributions makes opening iptables firewall ports very simple via the command line. Just be careful to not lock out access to the server by neglecting to open the ssh port.
lokkit -p 22:tcp -p 4505:tcp -p 4506:tcp
The system-config-firewall-tui command provides a text-based interface to modifying the firewall.
Different Linux distributions store their iptables rules in different places, which makes it difficult to standardize firewall documentation. Included are some of the more common locations, but your mileage may vary.
Fedora / RHEL / CentOS
Follow these instructions: http://wiki.debian.org/iptables
Once you've found your firewall rules, you'll need to add the two lines below to allow traffic on tcp/4505 and tcp/4506:
-A INPUT -m state --state new -m tcp -p tcp --dport 4505 -j ACCEPT -A INPUT -m state --state new -m tcp -p tcp --dport 4506 -j ACCEPT
Salt installs firewall rules in /etc/ufw/applications.d/salt.ufw. Enable with:
ufw allow salt
The BSD-family of operating systems uses packet filter (pf). The following example describes the additions to pf.conf needed to access the Salt master.
pass in on $int_if proto tcp from any to $int_if port 4505 pass in on $int_if proto tcp from any to $int_if port 4506
Once these additions have been made to the pf.conf the rules will need to be reloaded. This can be done using the pfctl command.
pfctl -vf /etc/pf.conf