[WinMac] Re: DCHP-based Intranet
Daniel L. Schwartz(expresso[at]snip.net)
I *knew* someone would take the bait... Please see below.
BTW, the lease time in NT's DHCP Server is adjustable; but as you'll see
From my April 23, 1999 posting to this very WinMac list, I quote
---------------
>>>>
Date: Fri, 23 Apr 1999 23:58:44 -0500
To: "The Windows-MacOS cooperation list"
From: "Daniel L. Schwartz" <<expresso@snip.net>
Subject: [WinMac] Mac DHCP client <<-> NT DHCP Server follow-up
Reply-To: "The Windows-MacOS cooperation list"
<<winmac@xerxes.frit.utexas.edu>
Sender: <<winmac@xerxes.frit.utexas.edu>
List-Software: LetterRip Pro 3.0.4 by Fog City Software, Inc.
List-Subscribe: <<mailto:winmac-on@xerxes.frit.utexas.edu>
List-Digest: <<mailto:winmac-digest@xerxes.frit.utexas.edu>
List-Unsubscribe: <<mailto:winmac-off@xerxes.frit.utexas.edu>
List-Archive: <<http://www.darryl.com/winmac/>
List-FAQ: <<http://www.darryl.com/winmacfaq/>
X-RCPT-TO: <<expresso@snip.net>
So, according to Mr. Droms, it *was* Apple screwing up on
this important issue, after all, by having the client starting in
INIT-REBOOT state *after* sending a DHCPRELEASE message upon previous
Mac shutdown.
Thanks are due to Mr. Droms and Ric Ford for bringing this
problem to a close.
Dan Schwartz
>>>>
>DHCP Standards
>Date: Sun, 18 Apr 1999 21:39:11 -0400
>To: notes@macintouch.com
>From: Ralph Droms (droms@bucknell.edu)
>Subject: DHCP problems with MacOS 8.5 and OT 2.02
>
>
>I'm writing in response to what appears to be considerable confusion
>about DHCP, OT 2.02 and various servers. I'm chair of the Dynamic
>Host Configuration working group (DHC WG) of the IETF and author of
>the DHCP specs. Here are some notes about the DHCP mail you posted
>recently.
>
>
>- Ralph Droms
> Chair, IETF DHC working group
> Computer Science Department
> Bucknell University
>
>
>
>
>* According to RFC 2131, when a DHCP client restarts, it is either
>in INIT state or INIT-REBOOT state. If the client doesn't have an IP
>address, it starts in INIT state and broadcasts a DHCPDISCOVER
>message to find a server willing to assign an address to the client.
>If the client has an IP address with an unexpired lease, it starts
>in INIT-REBOOT state and the client broadcasts a DHCPREQUEST message
>to confirm that its address is still valid.
>
>* There is another aspect to the behavior of the OT 2.02 client that
>has only recently been documented (Internet Draft
>draft-ietf-dhc-ipv4-autoconfig-04.txt). If the OT client receives no
>response to a DHCPDISCOVER message in INIT state, the client will
>select an address from the 169.254.0.0 subnet, which has been
>registered with IANA as the LINKLOCAL subnet. Recent Windows DHCP
>clients also use this autoconfiguration mechanism.
>
>* There was some not quite correct information about DHCP clients in
>one of the [reader notes]. A DHCP client always tries to contact a
>server when it restarts, whether or not it has an address with an
>unexpired lease, as described above. If a client in INIT-REBOOT
>state receives no response to its DHCPREQUEST messages, it assumes
>that its address is OK and continues to use its old address. Sending
>a DHCPRELEASE message is optional on the part of the client. If the
>client will not reuse the address again (i.e., the client is moving
>to a new network segment) or is willing to obtain a new address when
>it restarts, it may issue a DHCPREQUEST and restart in INIT state;
>otherwise, the client may remain silent at shutdown and restart in
>INIT-REBOOT state.
>
>* Based on RFC 2131, the behavior of OT 2.02, in which it restarts
>in INIT-REBOOT state after issuing a DHCPRELEASE at the previous
>shutdown, is incorrect. I've been in communication with the DHCP
>team at Apple; they understand that this behavior is incorrect and
>they plan to correct it.
>
>* When starting (incorrectly) in INIT-REBOOT state, after receiving
>no server response, the OT 2.02 Macs are following RFC 2131 and
>using their previous address. I'm a little surprised that the
>servers in question don't respond to the DHCPREQUEST for a released
>address with a DHCPNAK message. I'm also a little surprised that
>these Macs then revert to INIT state at the next use of OT; perhaps
>the lease on the reused address has timed out and the Mac was unable
>to extend the lease?
>
>
>
>[Follow-up]
>
>Date: Mon, 19 Apr 1999 08:32:23 -0400
>To: Ric Ford
>From: Ralph Droms
>
>
>There is an IETF page for the DHC WG,
>http://www.ietf.org/html.charters/dhc-charter.html and I run a
>DHCP-related site at http://www.dhcp.org
>
>- Ralph
>
>
>
>Rainoff Summary
>Date: Tue, 20 Apr 1999 16:21:17 -0400
>From: Adam Rainoff
>To: notes@macintouch.com
>Subject: DHCP and 8.5.1 comments
>
>
>Editor: I noticed much technical info posted. However, for the
>nontechnical, let me suggest the following post.
>
>Regarding the DHCP Issue & Mac OS 8.5.1
>
>The Bad news:www.P Issue & Mac OS 8.5.1
>
>Mac 0S 8.5.1 has a problem maintaining DHCP connections. This is the
>reason your ADSL or other DHCP service "drops". It's really not the
>provider's fault at all.
>
>The Good news:www.t all.
>
>Mac OS 8.6 fixes this problem, not only with ADSL, but with ALL DHCP
>services. The 8.6 update is scheduled for release sometime soon.
>
>Workaround:
>
>Reset your IP address by
>
>1) Open the TCP/IP control panel
>2) Change to "Using BootP Server"
>3) Close & Save
>4) Open the TCP/IP control panel
>5) Change to "Using DHCP Server"
>6) Close & Save
>
>
>Repeat if necessary. This will reset the IP and get you back online.
>
>
<<<<<<<<
-----------------------------------------------------------------
<<mailto:expresso@snip.net>
ALTERNATE: <<mailto:expresso@workmail.com>
Webmaster for <<http://www.Faulknerstudios.com>,
-> NEW! Sign up for the Mac-NT Mailing list at:
<<http://www.onelist.com/subscribe/Mac-NT>
-----------------------------------------------------------------
* Windows-MacOS Cooperation List *
<<<<<<<<
---------------
At 08:16 PM 7/7/99 -0500, Mike wrote:
>At 7:43 PM -0400 7/7/99, Daniel L. Schwartz wrote:
>>
>> Actually, almost all of the advice you have received is correct...
>>almost is only good enough in horseshoes & hand grenades!
>>
>> If you are running MacOS 8.5 or 8.5.1, you will need to select
>>Server" instead of "DHCP Server," in the TCP/IP control panel, due to
>>flaw in those versions of Open Transport. MacOS 8.6 fixed this known
>>(Apple) engineering bug.
>>
>> This bug manifests itself especially on networks that run the
>>DHCP Server
>>Service on Windows NT/Server. And, it's an Apple bug, not an NT bug.
>
>Again, an 'Apple' bug I have not seen manifest itself on anything but
>NT, and then only with insanely short lease times.
>
>
>-mab
* Windows-MacOS Cooperation List *
This archive was generated by hypermail 2.0b2 on Wed Jul 07 1999 - 18:43:45 PDT |