6 Replies Latest reply: May 8, 2012 10:59 PM by Bradford Chatterjee (CCIEx2/CCDE) RSS

    IPv6 to IPv4


      Hey guys,


      I need to know what ipv4 to ipv6 transition mthods i need to study for the route exam. i understand dualstack and tunnelling but i cant see how nat-pt fits in the real world.


      any advice on this would be great





        • 1. Re: IPv6 to IPv4

          Here is my quick summary.


          Dual-Stack:  (Bilingual)

          Our servers and/or gateways do it all.  IPv4/IPv6

                If you communicate in IPv6, go for it. Otherwise, IPv4 is okay too.


          Tunneling:  (kind of like VPN tunneling)

          ****, I have IPv6.   Our remote office has IPv6.

          But I need to jump this IPv4 puddle,  so we can communicate in IPv6.      

               Hey, I know.  I will tunnel over it.


          NAT:   (true translation of one to the other - vice versa)

          Let's just get along, and translate into the IP standard on the other side.

                *same as private IPs   to   public IPs   (NAT)


          Here are some practice session at GNS3VAULT.com

          • 2. Re: IPv6 to IPv4
            Bradford Chatterjee (CCIEx2/CCDE)

            NAT-PT is a method for IPv6-only hosts to communicate with IPv4-only hosts. Dual stack and the various forms of tunneling don't do any protocol translation, so even with those methods of IPv6 transition hosts must use IPv4 to talk to other IPv4 nodes and IPv6 to talk to other IPv6 nodes. You need a method of protocol translation like NAT-PT or NAT64/DNS64 for an IPv6-only node to talk to an IPv4-only node.


            Officially NAT-PT is deprecated by RFC4966 and is not a recommended transition mechanism, but it's still possible to configure and use it in your network. NAT64/DNS64 is now the preferred translation method.

            • 3. Re: IPv6 to IPv4

              Thanks guys,


              so the three i need to know for the exam are dual stack, tunneling and nat-pt.


              How extensivly do i need to know these?


              Is it a case of know what they do or am i going to need to set these up ?

              • 4. Re: IPv6 to IPv4

                I believe if you do those labs on gns3vault , you will have sufficient knowledge of tunnelling.   It actually strengthened my IPv6 knowledge all around.

                • 5. Re: IPv6 to IPv4
                  Scott Morris - CCDE/4xCCIE/2xJNCIE

                  There are lots of methods...   As El Tigre summarizes, that's what I'd concentrate on for the tests.


                  Yes, Bradford, NAT-PT is deprecated, and we'll see quite a lot of movement as people finally start deploying 15-year old technologies as something new.  However, the exams aren't quite that detailed, and they don't quite keep up with the latest and greatest in the standards anyway.


                  How many years after site-local addresses were deprecated did those things still get taught? 



                  • 6. Re: IPv6 to IPv4
                    Bradford Chatterjee (CCIEx2/CCDE)

                    I agree, I just think it's worth noting before someone goes out and does it for real.