The syntax in the video is actually correct.  This is a specific
technology known as NAT-PT, which is used for a very specific purpose
-- Getting IPv4 ONLY hosts to communicate with IPv6 ONLY hosts using
NAT mappings.

In the example in the video we have 2 hosts -- 1 host is IPv4 only and
the other host is IPv6 only.  This shows how to make the two
communicate.

IPv4 Host D -- 172.18.30.1
IPv6 Host A -- 3000:B00:FFFF:1::1

In this case, the command "ipv6 nat prefix 3ffe:b00:ffff:ffff::/96" is
used to determine the range for the NAT-PT. In other words, it says
"If I see something destined for something in this /96 range, do the
NAT-PT translation".  So, if Host A (IPv6 Host) sends a packet to
anything in that /96 range and the packet is sourced from
3000:b00:ffff:1::1 then what will happen is the NAT-PT router in the
middle will make the IPv4 source address 192.168.199.2 and send it
along the way to HostD

Let's look at it end-to-end.

1) Host A sends a ping to 3ffe:b00:ffff:ffff::a <--- in the /96 range
2) The NAT-PT gets this packet and realizes it is sourced from
3000:b00:ffff:1::1 and that it is destined for 3ffe:b00:ffff:ffff::a
3) The NAT-PT router creates an IPv4 packet sourced from 192.168.199.2
destined for 172.18.30.1.  It knows the destination IPv4 address due
to the static NAT configuration
4) Host D receives an IPv4 packet sourced from 192.168.199.2 and
destined for 172.18.30.1
5) Host D responds with an ICMP Echo-Reply sourced from 172.18.30.1
and destined for 192.168.199.2
6) The NAT-PT router gets this packet, and realizes it is sourced from
172.18.30.1 and that it is destined for 192.168.199.2
7) The NAT-PT router creates an IPv6 packet sourced from
3000:b00:ffff:ffff::a and destined for 3ffe:b00:ffff:1::1
8) HostA receives an IPv6 packet sourced from 3000:b00:ffff:ffff::a
and destined to 3ffe:b00:ffff:1::1

Check out this 
document:http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-nat_trnsln_ps6350_TSD_Products_Configuration_Guide_Chapter.html

On Sat, Feb 6, 2010 at 7:27 AM, Gian Paolo <[email protected]> wrote:
> Hi all,
> I'm watching VoD v4 video on IPv6. On 53:39 - static nat, the IPv6 range 
> dedicated to IPv6 translations is
>
>        ipv6 nat prefix 3ffe:b00:ffff:ffff::/96
>
> so shouldn't this command:
>
>        ipv6 nat v4v6 source 172.10.30.1 3000:b000:ffff:ffff::a
>
> be
>
>        ipv6 nat v4v6 source 172.10.30.1 3ffe:b00:ffff:ffff::a
>
> ???
>
>
> Thak you.
>
> Gian Paolo
> _______________________________________________
> For more information regarding industry leading CCIE Lab training, please 
> visit www.ipexpert.com
>



-- 
Regards,

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Sr. Technical Instructor - IPexpert
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