The filter table is mainly used for
filtering packets. We can match packets and filter them in whatever way we
want. This is the place that we actually take
action against packets and look at what they contain and
DROP or /ACCEPT them, depending on
their content. Of course we may also do prior filtering; however, this
particular table is the place for which filtering was designed. Almost all
targets are usable in this table. We will be more prolific about the filter
table here; however you now know that this table is the right place to do
your main filtering.
