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 succeeds the older patch-o-matic and patch-o-matic-ng packages. 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 the kernel need not be patched or recompiled, and usually, recompiling iptables is not necessary either. See the INSTALL file within the source package for the minimum requirements.