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<div class="moz-cite-prefix">On 08/01/13 19:51, Neff, Glen wrote:<br>
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<div dir="ltr"><font size="2" color="#000000" face="Tahoma">We
have proprietary network devices that use rely on DHCP for
configuration. We're using a standard 72 hour lease time,
and we rely on the IPs to not change, so long as these
devices aren't offline for much more than a reboot.</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">Static assignments by MAC
address are not feesible for our purposes.</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">The problem that we are
encountering is that periodically these devices must have
their firmware updated and these updates are causing the UID
sent in the DHCP request to be changed.</font></div>
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</blockquote>
<font face="tahoma">The main piece of information to identify a
client is actually the UID, so with a new UID -> a new client,
obviously it can not get the same IP, that is reserved for the old
client.<br>
You may have luck looking into classes and subclasses. Possibly
with "spawn". I have never used these features but I have a
feeling they may actually do what you need.<br>
Use the hardware = MAC to create your subclass and that could be
independant from the UID - I think.<br>
</font>
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cite="mid:F061F650C47E134C86F9605C5F44EE5F174AA481FB@MX23A.corp.emc.com"
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<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">Here's an example of three
entries taken from the dhcpd.leases file on the server:
<a moz-do-not-send="true" href="http://pastebin.ca/2299463">http://pastebin.ca/2299463</a></font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">The first entry was was
generated by a reboot early in the day.</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">The second entry was "control
case" reboot made before we updated the firmware on the
client device. Notice how it's identical to the first, with
the exception of the times.</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">The third entry is after the
firmware update. Notice that the MAC address remains the
same, however the UID has changed, so the server issued it a
new IP.</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">In consulting dhcpd.conf(5) I
found "deny duplicates;" which sounded like a magic bullet
workaround, so I added it to the subnet declaration in
dhcpd.conf file, but the problem remains the same (in tests
with other of the same type devices and firmware upgrade
scenario).</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">The server version is 4.2.4,
running on FreeBSD v8.2-RELEASE. It's built via the ports
system: isc-dhcp42-server-4.2.4_1</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">There is a DHCP-relay
involved - it's configured on the VLAN interface of a Cisco
Nexus 7010, running NX-OS v 5.2(3a).</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="tahoma">Any insite would be
appreciated.</font></div>
<div dir="ltr"> </div>
<div class="BodyFragment"><font size="2">
<div class="PlainText">-G<br>
<br>
/*<br>
* Glen R. J. Neff<br>
* USD Lab Operations Infrastructure Team<br>
* <a class="moz-txt-link-abbreviated" href="mailto:glen.neff@emc.com">glen.neff@emc.com</a><br>
*<br>
* EMC^2 == E^2<br>
*/</div>
</font></div>
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<pre class="moz-signature" cols="72">--
Best regards
Sten Carlsen
No improvements come from shouting:
"MALE BOVINE MANURE!!!"
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