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To: brian.somers@utell.net
Cc: brian@awfulhak.demon.co.uk, hackers@freebsd.org,
        tomy@dynamite.Stanford.EDU
Subject: Re: (wide) DHCP negotiation using the REQUEST_IPADDR option
In-Reply-To: Your message of "Fri, 10 Jan 1997 12:02:01 -0100"
References: <199701101202.MAA10949@ui-gate.utell.co.uk>
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Date: Fri, 17 Jan 1997 13:34:21 -0800
From: Akihiro Tominaga <tomy@gunpowder.Stanford.EDU>
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From: "Brian Somers" <brian.somers@utell.net>
Subject: (wide) DHCP negotiation using the REQUEST_IPADDR option
Date: Fri, 10 Jan 1997 12:02:01 -0100

> I'm not sure about the original logic behind returning -1 above.

There is a paragraph in the recent I-D, pg 32;

     If the network is correct, then the DHCP server should check if the
     client's notion of its IP address is correct. If not, then the
     server SHOULD send a DHCPNAK message to the client. If the DHCP
     server has no record of this client, then it MUST remain silent,
     and MAY output a warning to the network administrator. This
     behavior is necessary for peaceful coexistence of non-communicating
     DHCP servers on the same wire.

It is important if there are more than two servers in the same
segment.  If a server with an expired lease sends NAK, and a server
with a valid lease sends ACK, the behavior of the client depends on
which packet has arrived first.

# I may be wrong, because I don't catch up recent drafts well....
# If I'm wrong, please let me know.

> If anyone's interested in reproducing this, make sure that you delete the
> arp entry on the server box while the win95 box is shut down..... I wasted
> a lot of time here !

Thank you for your report.

Visiting Researcher of Stanford Univ.
Mosquito Net Project.
Keio Univ.
WIDE Project.
			Akihiro Tominaga (tomy@mosquitonet.stanford.edu)