Subject: [dhcwg] FORCE RENEW questions

From: "tm" <[email-masked]>
Date: Thu, 12 Dec 2002 10:21:30 +0100

Two questions:

A) Is DHCP FORCE RENEW supported by any operating system today? Or are there any known plans for it at Microsoft, Linux, BSD, etc.?

B) Is it possible to send a FORCE RENEW to a NIC that has not yet been configured with an IP address, that is, a NIC that never received a DHCP reply after reboot? (With the result that the host will do a DHCP request).

/TM

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From: "Barr Hibbs" <[email-masked]>
Date: Thu, 12 Dec 2002 21:09:37 -0800

I'm also interested in the answer to question (A) in the original message,
so would any responders please post their replies to the DHCWG mailing
list....  As an additional point, do the implementations of FORCERENEW also
implement DHCP Authentication [RFC 3118] as required by RFC 3203?

As to question (B), the NIC is not the DHCP client, so let me restate the
question and then answer it:  "Is it possible to send a FORCERENEW message
to an unconfigured client?"  As this message is unicast to a DHCP client,
and the client is directed to silently discard multicast messages, it is not
possible for an unconfigured client to receive a FORCERENEW message.  The
DHCP protocol [RFC 2131] describes how a DHCP client may continue
broadcasting DHCPDISCOVER messages if a DHCP server has not answered.  An
unconfigured client must not begin the protocol exchange with a DHCPREQUEST
message.  RFC 2131 also describes how a previously configured client may
recover from loss of contact with the server, but that is a different case
than you asked about.

--Barr Hibbs

  -----Original Message-----
  From: [email-masked] [mailto:[email-masked]]On Behalf Of tm
  Sent: Thursday, December 12, 2002 01:22
  To: [email-masked]
  Subject: [dhcwg] FORCE RENEW questions

  Two questions:

  A) Is DHCP FORCE RENEW supported by any operating system today? Or are
there any known plans for it at Microsoft, Linux, BSD, etc.?

  B) Is it possible to send a FORCE RENEW to a NIC that has not yet been
configured with an IP address, that is, a NIC that never received a DHCP
reply after reboot? (With the result that the host will do a DHCP request).

  /TM