Joshua Snyder (<josh_at_imagestream.com>) made a detailed picture about the IP packet flow on a Linux bridging firewall.
gute anleitung zum kompilieren eines realtime linux kernels
Alternatives MAC System für den Linux Kernel
Linux /proc IPv4 variable reference
To make the process of configuration easier, a new build target has been added: make localmodconfig. It runs "lsmod" to find all the modules loaded on the current running system