I'm using iptables for years, because it is a straightforward solution without any magic. But now I'm building a router for myself, I found there are many useful features provided by Shorewall.
Is it possible to use iptables and Shorewall on the same time? I know Shorewall is just a frontend of iptables. But I don't know whether cause a conflict.
Also, I need to block tons of addresses, so ipset is the perfect solution. Is it safe to use all these three firewalls?