IPv6 - Frequently Asked Questions (FAQ)

[dibyam-baral]

Is it possible to convert ipv4 to ipv6 address when we configure cisco router with ipv4 in one end and that provide ipv6 as an output in other end

If so then please help me with that command...

[James Leinweber]

In general IPv4 and IPv6 don't interoperate, and the single most problematic direction is trying to NAT v4 to v6; see e.g. RFC 4966 deprecating NAT-PT.  You want to plan for dual-stack operation with native IPv6 support from your upstream ISP instead.

-- Jim Leinweber, WI State Lab of Hygiene

[krun_shah]

If dual stack is not good option for you you may want to build pure IPv6 network with Stateless IP/ICMP Translations (SIIT) Disclaimer: Some applications like FTP and SIP will not work from IP network because it carries IP addresses in payload field of packet which no device could translate. Other thing that will break is multicast from IPv4 to IPv6.

[Phillip Remaker]

You have just asked a question that requires an entire book or two to answer, which has consumed legions of engineers for many years.  There are a lot of moving parts, depending on what you plan to do exactly, and a collection of possible techniques, a number of which require endpoint cooperation.

So the short answer is "no," in the absence of more details about what you hope to accomplish.  The long answer is "there are a number of IPv4 to IPv6 translation mechanisms you might use depending on your specific situation and each has a set of advantages and limitations." 

Without understanding exactly what you are trying to do, we can only refer you to books on IPv6.