N5. (WIP) Netfilter Internals

Links:

• intro to nftables
• netfilter developer docs
  • nftables internals
  • sets internals

These notes will mostly cover the nftable portion. The hooks into a netfilter are the same, but the way rules are created and composed is different for iptables.

We will start with a simple rule to count packets and see how this rule is actually implemented within netfilter. Next we will slowly improve and add parts to the rule to learn other features.