While most networking devices that do packet filtering have an implicit deny all built in as the last rule I always set one. I'm the type of person that likes to see things instead of assuming they exsist. (One of the many reasons I haven't bought into wireless networking.)
Since the default policies of the builtin packet filter chains are set to DROP, all traffic which did not match any other rule before is dropped. So there is no need to add extra dropping rules.
Hi all, do you need to set rules for in and for the answering of the same connection ? On my first ASL config i must this because of setting an "any - any - any -drop" rule as the last one.
One thing to think about is that there's two different drop, the one that's called only drop (the other one log drop) also make it to not show in the log file. So if you are interested in log files, you should change to log drop.