Where does iptables log?

Question

I am trying to debug iptables as described here but it doesn't look like any logging is happening.

System is a Linux raspberrypi 4.9.59+ Kernel / Raspbian GNU/Linux 9 (stretch).

Any ideas as to why and how to correct this?

Answer 1

The log are generated by the kernel and should appear as kern.warning: in Debian that goes to /var/log/kern.log.

However, iptables won't log anything by default. You must enable logging with iptables -A INPUT -j LOG or with some more specific rule.