In a message written on Mon, Jun 13, 2011 at 05:41:12PM -0700, Owen DeLong wrote:
The IPv4 host does this once and gets its lease. If there is no DHCPv6 server then DHCPv6 clients would keep broadcasting forever. Not a good thing.
Which is no worse than the behavior of an IPv4 host on a network without a DHCP server.
I understand on some level why the IETF doesn't want DHCPv4 to be able to hand out IPv6 stuff, and doesn't want DHCPv6 to hand out IPv4 stuff. In the long run if you assume we transition to IPv6 and run only IPv6 for years after that it makes sense. However, I do think a single option is needed in both, "ProtocolsAvailable". Today it could have "4" or "6", or "4,6". In the future, who knows. The idea being if I am a dual stacked host and I do DHCPv4 and get back that only 4 is available, I might stop doing DHCPv6 or at least make my exponential backoff even more exponential. Similarly, if I get back "4,6", I might know to immediately try the other protocol as well. This would allow end stations to greatly optimize their behavior at all stages of deployment. -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/