Using /126 for IPv6 router links

Jim Burwell jimb at
Wed Jan 27 15:39:34 UTC 2010

On 1/26/2010 23:32, Mark Smith wrote:
> A minor data point to this, Linux looks to be implementing the
> subnet-router anycast address when IPv6 forwarding is enabled, as it's
> specifying Solicited-Node multicast address membership for the
> all zeros node address in it's MLD announcements when an interface
> comes up.
Yes, I believe you are correct.  It appears to be implemented.  When I
ping the subnet anycast from a Linux or Windows XP box I get a reply
from the IPv6 router on my LAN.  The router is a Linux box running
Kernel 2.6.31.  Interestingly, on a Linux box, the ping6 command shows
the router's unicast address answering the pings (same goes for ping6
under Cygwin on a Windows box).  But on a Windows box ping shows the
anycast address answering.  However, in both cases packet captures show
it actually is the unicast address of the router answering, which I
believe is the expected behavior.  Windows ping just shows the wrong
address for whatever reason.

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