IPv6 Deployment for the LAN

Ray Soucy rps at maine.edu
Sun Oct 18 01:38:26 UTC 2009


> I thought someone had to respond to router solicitations for stateless
> autoconfig of global scope addresses to happen. On Linux you just
> don't run the radvd. On Cisco I think it's something like "ipv6 nd
> suppress-ra" in the interface config. Does that fail to prevent
> stateless autoconfig? Or is there a problem with the operation of
> DHCPv6 if router advertisements aren't happening from the router?

The "ipv6 nd suppress-ra" config will only suppress unsolicited RA, it
will still respond to RA solicitations.  Load it up in Wireshark and
you'll see.  A lot of host implementations of IPv6 seem to enable
SLAAC as soon as they see any 64-bit prefix regardless of what flags
are set.

Making assumptions about IPv6 has proven to be unwise in my experience.

So far, the only thing that I've seen that is close to working is to
configure the router to not advertise the 64-bit prefix using "ipv6 nd
prefix <prefix> no-advertise", but at that point it seems easier to
just go with a 80-bit prefix and remove any doubt.

-- 

Ray Soucy
Communications Specialist

+1 (207) 561-3526

Communications and Network Services

University of Maine System
http://www.maine.edu/




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