Subject: WG ACTION: ACCEPT [LL40] IPv4 LL does not alter the behavior of the DHCPv4 state machine

From: Erik Guttman <[email-masked]>
Date: Mon, 05 Jan 2004 20:27:53 +0100

Accepting this issue has the following implications:
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Add this new section:

2.12 Interaction between DHCPv4 client and IPv4ll state machines

A device that implements both IPv4ll and a DHCPv4 client should not alter 
the behavior of the DHCPv4 client to accommodate IPv4 Link-Local 
configuration. In particular configuration of an IPv4 Link-Local address, 
whether or not a DHCP server is currently responding, is not sufficient 
reason to unconfigure a valid DHCP lease, to stop the DHCP client from 
attempting to acquire a new IP address, to change DHCP timeouts or to 
change the behaviour of the DHCP state machine in any other way.

Several early implementations of IPv4 link-local have modified the DHCP 
state machine in an attempt to make IPv4 link-local more reliable, and the 
field experience we have gained from this has shown that it does not work 
- reliability of DHCP service is significantly reduced.   If increased 
reliability of IPv4 link-local is desired, we recommend that the IPv4 
link-local state machine track the DHCP client state machine and, in cases 
where it is not certain that the DHCP-assigned address is correct, the 
IPv4ll state machine acquire an IPv4ll address without causing the DHCP 
state machine to relinquish its address.

Further discussion of this issue is provided in [DNAv4].

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Add a reference to DNAv4

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Please see: http://www.merit.edu/mail.archives/zeroconf/msg00004.html
And: http://www.drizzle.org/~aboba/ZEROCONF/ll40.html

Regards,

Erik