Linux - setting iptables on ubuntu

@https://www.digitalocean.com/community/articles/how-to-set-up-a-firewall-using-ip-tables-on-ubuntu-12-04

$ iptables -A INPUT -p tcp --dport ssh -j ACCEPT
$ iptables -A INPUT -p tcp --dport 80 -j ACCEPT
$ apt-get install iptables-persistent
@yes, yes
$ service iptables-persistent start