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Is it possible for an IPv4-compatible IPv6 device to have only one IPv6 address?
For example, when device-A talks to an IPv4 device, device-A communicates using its IPv4 address 2.2.2.4. Later, when device-A talks to an IPv6 device, can it use its IPv6 address ::2.2.2.4?
Or must all IPv4-compatible IPv6 device have two IPv6 addresses?
Why are you saying it must have two IPv6 addresses? In your example what will be the two addresses? – fmanco – 2012-07-13T01:42:35.967
@criziot Since device-A can't talk to IPv6 devices using his address ::2.2.2.4 (reserved IPv6 address), he needs to use another IPv6 address to talk to IPv6 devices right? – Pacerier – 2012-07-13T02:08:35.670
1Ok. I got it. But as @Sander Steffann said, ::2.2.2.4 isn't used anymore. You usually have an autoconfigured IPv6 for link local and eventually a global address if you have an IPv6 capable router. But none of those are related with the IPv4 address you may have. – fmanco – 2012-07-13T06:25:57.760
@criziot So before automatic tunneling was deprecated, each IPv4-compatible IPv6 device has 1 IPv4 address + 2 IPv6 addresses = 3 address per device? – Pacerier – 2012-07-13T06:35:28.763
2Yes. You allays need a link local address, and if you want to communicate with a machine in other network you will need a global address since link local addresses are only valid within the link. So 2 IPv6 plus the IPv4. – fmanco – 2012-07-13T12:32:00.377