If the iptables-ipv6 package is installed, netfilter under Red Hat Enterprise Linux can filter the next-generation IPv6 Internet protocol. The command used to manipulate the IPv6 netfilter is ip6tables. Most directives for this command are identical to those used for iptables, except the nat table is not yet supported. This means that it is not yet possible to perform IPv6 network address translation tasks, such as masquerading and port forwarding.
Saved rules for ip6tables are stored in the /etc/sysconfig/ip6tables file. Old rules saved by the ip6tables initscripts are saved in the /etc/sysconfig/ip6tables.save file.
The configuration file for ip6tables initscript is /etc/sysconfig/ip6tables-config and the names for each directive vary slightly. For instance, the iptables-config directive IPTABLES_MODULES is IP6TABLES_MODULES in the ip6tables-config file.