IPv6 NAT

Posted Jul 22, 2011 15:48 UTC (Fri) by raven667 (subscriber, #5198)
In reply to: IPv6 NAT by Cyberax
Parent article: IPv6 NAT

Service discovery is still a problem in IPv4 which is why protocols such as mDNS exist but there is also standard ways of discovering neighbors in IPv6 such as pinging the all hosts multicast address ff02::1. Manually putting addresses in DNS is certainly not out of the question either, just because you have a slightly longer address string.

Sure there are operational changes with IPv6 and there will be rough edges that need to be refined that will become more apparent as it is used more. Think about the difference between a modern IPv4 implementation such as in Linux vs. IPv4 of 10 or 20 years ago. The protocols are compatible but the implementation and management are very different. Implementations can be modified to support quick prefix changes without changing any of the local subnetting or addressing in a compatible way, if that is the way the market goes.

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IPv6 NAT

Posted Jul 22, 2011 20:29 UTC (Fri) by Cyberax (✭ supporter ✭, #52523) [Link]

>Service discovery is still a problem in IPv4 which is why protocols such as mDNS exist but there is also standard ways of discovering neighbors in IPv6 such as pinging the all hosts multicast address ff02::1.

That's so incredibly unreliable and convoluted, that it actually might be used.

>Manually putting addresses in DNS is certainly not out of the question either, just because you have a slightly longer address string.
It is out of the question. Addresses are not 'slightly' longer, they are ten _times_ longer in practice.

In IPv4 world one just needs to remember _one_ _octet_ in practice. Because three other octets are usually fixed in a typical NAT-ed network. In IPv6 world one needs to remember at least 8 octets.

And no, assigning the second half of the IPv6 manually won't work. I have not yet seen a device that can accept a prefix advertisement AND allow to assign the postfix manually. And you'll need it to make renumbering even a remotely possible alternative.

>Sure there are operational changes with IPv6 and there will be rough edges that need to be refined that will become more apparent as it is used more. Think about the difference between a modern IPv4 implementation such as in Linux vs. IPv4 of 10 or 20 years ago.

Not true. IPv4 networks 10 years were administered almost exactly like today. Even 15 years ago situation was not that much different (well, we used HTTP proxies instead of NATs, relied more on manual assignment than on DHCP but that's basically all).

IPv6 is right now NOT READY for the real world. The basic protocol is fine, but everything else starting from DHCPv6 and SLAAC is utterly and horribly broken.

/me wants to hit IETF members with a lead pipe. Repeatedly.