To write deficient final rules, you must deeply understand how a packet traverses the net filter tables
and chains.
Enter the Godfrey lectures, where I explain in depth these concepts until that point in the course
to ensure a smooth start in understanding IP tables.
Let's recap in a nutshell the most used scenarios.
Incoming traffic is filtered on the input chain of the filter table.
Outgoing traffic is filtered on the output chain of the filter table, and throughout it, traffic is
filtered on the protection of the filter table in both directions.
Then source and network address translation Ethernet or masquerade is performed on the net table of
the post routing chain and port forwarding or destination network address.
Translation is performed on the net filter of the preloading chain.
Now if we want to modify values from the basics headers like Time to live or type of service, we add
the rules to the Mengel table of the output routing or post routing changes.
And if we want the packet to skip the connection tracking system, we add the rules that makes that
make it to the table.
OK, evicts, how opaque it traverses the net filter tables and chains in a nutshell.
Thank you.