log line question
Simon Hobson
dhcp1 at thehobsons.co.uk
Mon Dec 13 17:30:08 UTC 2010
Bruce Hudson wrote:
>What I recall was that the basic process
>involved (1) the client broadcast a DISCOVER, (2) potentially multiple
>servers OFFERed, (3) the client selected an offer by some unspecified
>mechanism and broadcast a REQUEST, including the server identifier of
>the server is chose, and (4) only that server ACKed (or NAKed) the
>request.
If you put the client to sleep, unplug it's network cable, or
whatever - when it comes back up on the network it is not supposed to
use it's existing lease without checking to see it's still valid (you
may have plugged it into another network).
So the client, if it has persistent storage and an unexpired lease,
should broadcast a request for the address it wants to use. If it's
on a different network with a DHCP server, the other server then has
the opportunity to NACK the request - and then the client can discard
the lease, and go back to step 1 and broadcast a discover.
Having said that, I've just checked, and my Mac doesn't include
option 54 (Server Identifier) either when bringing up an interface or
when forcing a renewal through the Network settings control panel.
Looking through the server logs, it looks like it's only sent (by
Macs) at step 3 above.
My DHCP Handbook is at work so I can't look that up right now.
--
Simon Hobson
Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.
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