SLAAC(autoconfig) vs DHCPv6

Dale W. Carder dwcarder at
Mon Aug 18 15:23:58 CDT 2008

Hey Scott,

On Aug 18, 2008, at 2:33 PM, Scott Weeks wrote:
> From: "TJ" <trejrco at>
> As a general rule, most clients are following the "If we gave them  
> static
> IPv4 addresses we will give them static IPv6  
> addresses" (infrastructure,
> servers, etc).  The whole SLAAC(autoconfig) vs DHCPv6 is a separate  
> (albeit
> related) conversation ...
> ----------------------------------------------------
> I'm still an IPv6 wussie and would like to learn more before moving  
> forward, so would anyone care to share info on experiences with this  
> decision?

Here's some pro's and con's to both

- widely implemented in host v6 stacks that have shipped
- widely implemented on v6 routers
- really, really, really broken: it didn't support handing out
   any DNS info until RFC 5006, thus SLAAC still requires human
   intervention on a client to make "teh v6 interwebs" work.  It
   will probably be a painful wait until 5006 gets more widely
   implemented on hosts (if ever, for some) & routers.
- probably "faster" than dhcpv6 w/ tuning timers.  Could be
   better for mobile thingys.
- supports RFC 3041 "security by obscurity" extensions.

- doesn't ship w/ some OS's
- new (danger code), not all features implemented
- router support for dhcpv6 relay very limited
- advanced things like prefix delegation don't really seem to
   have been ironed out.

In case you weren't confused enough between the two, they are not
mutually exclusive.  You can run both SLAAC and DHCPv6 at the same
time on the same L2.

Links for (2) dhcpv6 implementations:


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