iptables and netfilter are building blocks of a framework inside the Linux 2.4.x and 2.6.x kernel.
netfilter, iptables and the connection tracking as well as the NAT subsystem together build the whole framework.
Here are some key features of "iptables":
· stateless packet filtering (IPv4 and IPv6)
· stateful packet filtering (IPv4)
· all kinds of network address and port translation (NAT/NAPT)
· flexible and extensible infrastructure
· multiple layers of API's for 3rd party extensions
· large number of plugins/modules kept in 'patch-o-matic' repository
What's New in This Release: [ read full changelog ]
· This version includes aliasing support, which translates command lines using obsolete extensions into new ones.
· The option parser now flags illegal negative numbers in some more extensions.
· A division by zero was resolved in libxt_limit as well.