Running DHCPv6 relay without interfaces

Peter Rathlev peter at
Thu Mar 14 17:31:47 UTC 2013

On Thu, 2013-03-14 at 10:10 -0700, Chris Buxton wrote:
> On Mar 14, 2013, at 6:40 AM, Peter Rathlev wrote:
> > For DHCPv6 you could also route the FF02::1:2 address to the DHCP server
> > but that would require L3 multicast routing.
> I believe the correct address for site-wide routing of the request
> would be FF05::1:2, not FF02::1:2. Multicast routing is something that
> should be implemented in an IPv6 world.

Hmm... We're an enterprise and for us it's probably relatively easy to
implement company wide, but multicast routing in the Internet? Doesn't
IPv6 multicast routing still require state-keeping like in IPv4?

Maybe I'm too locked into IPv4-think but I'm more comfortable with a
local relay and FF02::1:2, at least when considering debugging, than
relying on working multicast routing.
> Another option would be to join the entire site into a single IPv6
> vlan (separate from the smaller IPv4 vlans) and put the DHCPv6 server
> directly on that vlan. No broadcast can mean larger vlans in an IPv6
> world.

But if you have e.g. some 150 different physical sites and want to serve
everything from a couple of centralised DHCP servers you would need
relaying (or multicast routing of FF05::1:3).


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