v6 & DSL / Cable modems

Nathan Ward nanog at daork.net
Sat Feb 7 06:51:36 UTC 2009

On 7/02/2009, at 10:29 AM, David W. Hankins wrote:

>> I want built in multiple IP bindings on my hosts. I'd like (Windows 7
> I suppose you can individually configure every host to get itself
> temporary addresses from RA announcements.  This isn't usually a
> good default configuration, but OS implementation already seems to
> be inconsistent on the default configuration here.  So we're back to
> the IPv4 dark ages where you have to walk around to all the devices to
> effect changes in policy (beyond prefix field contents).

I'm not sure, but you seem to be implying that you need to configure  
hosts to tell them to use RA or DHCPv6 to get addresses. My apologies  
if this is not your intention.

RA messages are always going to be sent by routers and received by  
hosts, even if DHCPv6 is being used for address assignment.

The RA message tells the host either "here is a prefix, number  
yourself out of it" or "go to the DHCPv6 server to get an address".

OS implementation here is identical - one does not configure a host to  
listen for RA messages or to request addresses from DHCPv6, the host  
*always* listens for RA messages. Changing from SLAAC to DHCPv6 based  
address assignment only requires touching the router sending the RA  

Nathan Ward

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