Re: Multiple addresses [was Node Requirements: Elevating DHCPv6 from MAY to SHOULD]

[james woodyatt <[e-mail]>]

On May 30, 2011, at 7:38 PM, Fred Baker wrote:
> 
> [...] IPv6 systems come, at least today, with SLAAC as the default. So there is a requirement to configure DHCPv6, at least from that perspective. That said, SLAAC ain't gonna happen in the absence of RAs, and you can disable RAs on the router. So if an interface comes up and no RA is forthcoming, I could imagine the thing probing with a DHCPv6 request. [...]

For what it's worth, the behavior of Apple's iOS 4.3 and later is straightforward.  If there is no RA, then there is no IPv6.  iOS 4.3 doesn't support manual IPv6 configuration, so automatic configuration is the only way to plumb it.  The DHCPv6 client only starts if the router indicates availability with O=1.  Remember when I was complaining that we needed RFC 6106 for the O=0 case?  Given that we have that, I don't see any benefit to starting the DHCPv6 client unless a router explicitly tells us to expect service.  No router?  No need for dynamic host configuration.


--
james woodyatt <[e-mail]>
member of technical staff, core os networking