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I've got a VPS with IPv4 and IPv6 addresses, and I'd like to use them both for my website and other services I might use. I've added a "www" register both with "A" and "AAAA", and I've done the same for the "ns" register. Is this "the Right Way", or should I use different names for the IPv6 part? (i.e., "www6", "ns6", etc.)

Thanks in advance.

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up vote 8 down vote accepted

IMHO, it depends on what you want.

If you're using both protocols (v4 and v6) to offer the same service (eg IMAP/S, or HTTP, or whatever), and you want clients to be protocol-transparent - that is to say, if you want v6-enabled clients to use v6, and others to use v4, and no-one to care about which they're using - then use the same hostname in each record.

If you want people to be able to select protocol by hostname, use different hostnames for A and AAAA records.

So, for my webserver, where I want clients to be protocol-agnostic, I use the same hostname:   3600    IN  A   3600    IN  AAAA    2a01:8000:0:4::1:1

For my ntp pool server, where I decided I'd like people to be able to select the protocol, I used different ones:   3600    IN  A  3600    IN  AAAA    2a01:8000:0:4::123:123

Work out what client behaviour you wish to encourage, and make policy accordingly.

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Thanks, that clears it up. – rsuarez Nov 6 '12 at 11:32

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