IPv6 RA vs DHCPv6 - The chosen one?

Fri Dec 23 21:22:09 UTC 2011

On Fri, 23 Dec 2011, Tomas Podermanski wrote:

> 
> 
> It sounds good, but according to  RFC 6434 ( IPv6 Node Requirements) SLAAC is required, but DHCPv6 is only optional. So any
> manufacturer of operating systems or devices do not have to support DHCPv6.

You might propose updating RFC 6434

>
>       Administrators are deliberately providing conflicting information?
> 
> 
> Not administrators, but attackers then could have more ways for harmful activity.

That is why you are administrator - closely monitor your network.

>
>       Some operating system do the SLAAC processing in user space. What is the problem.
> 
> 
> As I wrote. Troubleshooting is more difficult.

Both can difficult to troubleshhoot

> 
>
>             - DHCPv6 is currently tied with SLAAC (M,O flags), what means that
>              a DHCPv6 client have to wait until some RA message arrives to start DHCPv6
>              discovery. That unnecessary prolongs whole autoconfiguration process.
> 
>
>       I think it is matter of implementation.
> 
> 
> Because DHCPv6 is depended on a information provided by SLAAC (RA messages) and DHCPv6 client have to wait. I hope that this dependency
> will disappear when the route option is added into DHCPv6. Nice thread on this topic is on
> http://www.ietf.org/mail-archive/web/dhcwg/current/msg12183.html.

In my opinion client can ask address via DHPv6 without paying 
attention to RA messages.

> 
> 
> Agree, can be another advantage. But in fact it seems that networks with thousand devices will rather prefer dhcpv6 instead.

As other already mentioned: SLAAC for less controlled, more resource 
concerned environment. DHCPv6 for more tightly controlled ones.

Best Regards,
 	Janos Mohacsi