In your letter dated Tue, 31 May 2011 14:45:24 +0200 you wrote: >Is DHCPv6 more expensive than DHCPv4? Since even the most minimalistic = >device with IPv4 support I know of has DHCPv4 support; however, you = >might be referring to devices even more minimalistic than what I have in = >mind.
I wasn't there. Similar arguments were repeated for the DNS option in the RA: a stateless DHCPv6 query was too much hassle. >As a programmer, I don't believe in randomness but in predictability. = >You don't write code that will only crash in one out of hundred billion = >cases if you can write code that will never crash for sure - even if the = >first case is so unlikely, that you may never see the code crash in your = >whole life. The question is, what do you gain? Do you expect an actual increase in reliability? If there are many thing that can go wrong and are likely to go wrong, then changing one possible fault from very unlikely to designed to be impossible doesn't really contribute to the overall reliability of the system. >However, we are losing the point here: With IPv6 I just fail to see the = >argument SLAAC vs DHCPv6, since there is no real reason IMHO for = >either/or and I fail to see how this is helpful if there are networks = >based on SLAAC and networks based on DHCPv6, this only adds unnecessary = >inconsistency. And people make it even worse by requesting a flag to = >control whether nodes may use privacy extension or not. Why not make it = >consistent: Every network is always SLAAC, even if there is a DHCP = >server, it is SLAAC. Privacy Extension is always possible to protect = >people's privacy if they feel like it. And only DHCP is optional, but = >when it is available, it does not replace SLAAC, it "completes" it and = >either hands out an IP address or not, but even when it hands out an IP = >address, it does not replace SLAAC. And thus I don't really see any need = >for an M or O flag in a RA message. Clients supporting DHCP will always = >try DHCP when a link comes up. Really, this traffic is so little = >compared to current network speeds, it's absolutely insignificant. You get turning SLAAC on and off for free (you need that flag to be able to mark a prefix as on-link without allowing hosts to use that prefix as source address). As far as I know, the ability to turn DHCPv6 on or off was based on the amount of network traffic it would generate, so you also get that more of less for free. Privacy extension are tricky. The owner of the host and the owner of the network may have conflicting interests. I'm sure that all network operators would agree with hosts generally preferring addresses with privacy extensions. -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
