dhcpcd and multiple IPv6 gateways on one interface

[Roy Bixler <rcbixler%nyx.net@localhost>]

On a NetBSD 7.1 system, after a network upgrade by the administrator
(not me), I see frequent messages in /var/log/messages like this:

dhcpcd[nnnn]: ab0: changing default route via fe80::xxx:xxxx:xxxx:xxxx
dhcpcd[nnnn]: ab0: fe80::xxx:xxxx:xxxx:xxxx: router expired

I believe that the administrator set up the network with 2 routers
which are both active and advertising routes.  I'm seeing the result,
which looks like route flap.  I have a Linux system available and I
don't see the same thing with it.  It configures multiple default IPv6
gateways on the same interface and just hums along.  Can NetBSD do the
same thing?  Except for the log spam, the NetBSD system works fine
with this router setup and IPv6.  I can just ignore the log spam, but
is there a better approach?

-- 
Roy Bixler <rcbixler%nyx.net@localhost>
"The fundamental principle of science, the definition almost, is this: the
sole test of the validity of any idea is experiment."
-- Richard P. Feynman