Re: new issue: LL34 Better transition to routable from v4LL using DHCP

    Date:        Thu, 11 Sep 2003 20:34:27 +0300
    From:        Mika Liljeberg <[email protected]>
    Message-ID:  <1063301667.777.22.camel@hades>

  | Frequent polling is also a very bad idea from the standpoint of power
  | efficiency. Not all devices are tethered to a power outlet.

Yes.

  | This is really a DHCP issue but it would seem preferable to have DHCP
  | servers announce their presence (and readines to assign addresses) with
  | a periodic broadcast, rather than have all the clients broadcasting in
  | an effort to locate a server.

This is real hard to achieve - the clients can be almost anywhere, they're
not all on the same LAN as the DHCP server.   For this to be practical, the
DHCP server would need to know where all its possible relay agents were
located, and enlist their help in sending that kind of message.   That's
not something that a typical dhcp server knows now.

  | Alternatively, I suppose servers could just periodically broadcast an
  | unsolicited DHCPOFFER,

Same problem.

That's why watching for responses to someone else's queries can possibly
be a help.   Where it falls down is when there is no-one else to make
queries, that is, there's just one node.   If there was a way for a node
to know how many other clients existed (on the same LAN at least) then
nodes could backoff to a fixed query/second rate (for the LAN), but as
things are currently, there's no good way I know of to perform that count.

kre