Linux netfilter Hacking HOWTO: Netfilter Architecture

Next Previous Contents 3. Netfilter Architecture Netfilter is merely a series of hooks in various points in a protocol stack (at this stage, IPv4, IPv6 and DECnet). The (idealized) IPv4 traversal diagram looks like the following: A Packet Traversing the Netfilter System: --->[1]--->[ROUTE]--->[3]--->[4]---> | ^ | | | [ROUTE] v | [2] [5] | ^ | | v | On the left is where packets come in: having pass