IPv6 vs IPv4

In terms of forwarding, filtering and policing, IPv6 is not really all that different from IPv4. The most noticeable difference is that the command is called instead, but all the options, apart from some really protocol-specific ones, are the same. Ipset options are no exception: you can use the same format with both and

and there are no tricks to remember.

Other options have differently named counterparts in IPv6: the time to live field is called TTL (-

in IPv4 and HL (which stands for ‘hop limit’) in IPv6. The IPv6 equivalent is

Another example is the ICMP protocol, which is slightly different for IPv6. The option for ICMP messages is

Of course, there are certain options that have no IPv4 counterparts. Those include the Mobility Header used in mobile IPv6, Destination Options, the Hop-by-Hop Options header, and a few more. However, these are nowhere as widely used as options like source and destination address. None of your iptables knowledge is lost in transition to IPv6.

As the internet gradually switches over to IPv6, now is the time to start learning about the protocol. Fortunately, many options are similar to IPv4.