Changes

On other change IPv6 introduces compared to IPv4 is that additional ICMP traffic flows are necessary for normal network signalling whereas it was predominantly used for failure-case reporting in IPv4 networks. This requires IPv6 firewalls to admit certain ICMPv6 traffic flows in order to handle IPv6 address allocation, neighbour discovery and several other IPv6 processes. For many client devices this will be handled directly by the firewall itself, but if you are developing your own IPv6 firewall then you need to ensure you follow [http://www.ietf.org/rfc/rfc4890.txt RFC4890] which includes an ip6tables packet filter example.

One other change IPv6 introduces compared to IPv4 is that additional ICMP traffic flows are necessary for normal protocol signalling whereas it was predominantly used for error-case reporting in IPv4 networks. This requires IPv6 firewalls to admit certain [[ICMPv6_Types_Codes]] in order to handle IPv6 address allocation, neighbour discovery and several other IPv6 processes. For many client devices this will be handled directly by the firewall itself, but if you are developing your own IPv6 firewall then you need to ensure you follow [http://www.ietf.org/rfc/rfc4890.txt RFC4890] which includes an ip6tables packet filter example.