A=1 L=0 PIO

Bjørn Mork bjorn at mork.no
Tue Aug 16 13:45:16 CEST 2016


Mikael Abrahamsson <swmike at swm.pp.se> writes:
> On Tue, 16 Aug 2016, Sander Steffann wrote:
>
>>> I'm trying to figure out what a "normal" currently deployed in the field IPv6 host would do if it receives an RA with PIO /64 where L=0 and A=1.
>>
>> On an implementation level what I have seen on Linux is that the L flag determines whether the route 2001:db8::/64 -> eth0 is installed or not.
>
> Ok, thanks everybody. So it'll still do A=1 style addressing (EUI64,
> privacy extension addressing etc)? Will it perform DAD?

Use the source, Luke1

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/net/ipv6/addrconf.c#n2523

That is:

 if (L) then add route
 if (A) then do autoconf

Without any side looking at the other flag.  Specifically: The value of
L does not affect the interpretation of A.  Which is pretty much what
RFC 4861 says too, AFAICT

So the answers to both your questions is "yes".


Bjørn


More information about the ipv6-ops mailing list