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Table of Contents
Firewalls
IPfire
The office LAN uses IPfire, a Linux firewall distro.
iptables
I like using quicktables to setup a basic IPtables ruleset quickly.
Setting up a Firewall
Before setting up a firewall, it's a good idea to setup a cron job that will reset it in case something goes wrong.
CentOS
CentOS by default does not save the ruleset on restart.
The system configuration is at /etc/sysconfig/iptables-config
*/5 * * * * /etc/init.d/iptables restart
FTP
$iptables -A INPUT -p tcp --dport 20 -j ACCEPT $iptables -A INPUT -p tcp --dport 21 -j ACCEPT $iptables -A INPUT -p tcp --dport 50000:50400 -j ACCEPT
Netatalk
$iptables -A INPUT -p tcp -s 192.168.1.0/24 --dport 548 -j ACCEPT $iptables -A INPUT -p tcp -s 10.117.209.0/24 --dport 548 -j ACCEPT
Monit
$iptables -A INPUT -p tcp -s 192.168.1.0/24 --dport 2812 -j ACCEPT
Multicast DNS
The avahi daemon uses multicast DNS to advertise services on the network.
$iptables -A INPUT -p udp --dport 5353 -d 224.0.0.251 -j ACCEPT $iptables -A OUTPUT -p udp --dport 5353 -d 224.0.0.251 -j ACCEPT
Samba
$iptables -A INPUT -p tcp -s 192.168.1.0/24 --dport 445 -j ACCEPT
quicktables
You can use quicktables to quickly generate a simple firewall rules set.
