Xtables-addons is a set of additional extensions for the Xtables packet filter that is present in the Linux kernel (which is loosely known by its administrative commands iptables/ip6tables/etc.).
Xtables-addons is the successor to patch-o-matic(-ng). Likewise, it contains extensions that were not, or are not yet, accepted in the main kernel/iptables packages.
Xtables-addons is different from patch-o-matic in that you do
not have to patch or recompile the kernel, sometimes recompiling iptables is
also not needed. See the
file for the minimum requirements of this package.
patch-o-matic suffered from a number of problems:
Send anything Xtables-addons related to the
netfilter-devel list that is handled through vger.kernel.org or
various alternate services, such as Gmane. Subscription is not necessary,
just post to it.