I use iptables-persistent to set firewall rules.
This is my standard configuration:
*filter :INPUT DROP [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -p tcp --dport 2123 -m mac --mac-source XX:XX:XX:XX:XX:XX -j ACCEPT COMMIT
Problem is I can't download packages from debian servers and ping local and external IP addresses.
INPUT is only for 'incoming' connections, is this correct?
These are the rules for IPv6:
*filter :INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT DROP [0:0] COMMIT