<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Don,</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature"> the loss of connectivity issue should have</div><div id="AppleMailSignature">nothing to do with the lease duration, as</div><div id="AppleMailSignature">any sane dhcp client renews at the lease</div><div id="AppleMailSignature">midway point, in any case.</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">This means that if your users had always</div><div id="AppleMailSignature">been getting a 20-minute initial lease time,</div><div id="AppleMailSignature">they might only have noticed that during</div><div id="AppleMailSignature">the first 10 minutes of the lease -- after that,</div><div id="AppleMailSignature">it would always be the 24-hour lease.</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">We had some users being losing network</div><div id="AppleMailSignature">connectivity about an hour after docking</div><div id="AppleMailSignature">their laptops on Monday morning; it turned</div><div id="AppleMailSignature">out to be a complex interaction between the</div><div id="AppleMailSignature">Cisco NAM Client, our DHCP failover peers,</div><div id="AppleMailSignature">and the Cisco switches doing DHCP Snooping.</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">Mark S</div><div><br>On Oct 26, 2015, at 10:36, Gregory Sloop <<a href="mailto:gregs@sloop.net">gregs@sloop.net</a>> wrote:<br><br></div><blockquote type="cite"><div><title>Re: 20 minute leases</title>
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<span style=" font-family:'Courier New'; font-size: 9pt;">You're looking for something more definitive, it seems - which I don't have. I do believe that quite a lot of work went into fail-over since 4.1 - there are a couple more options that help a fail-over situation survive a peer down situation better [especially in a tight IP pool] and the like. So, I suspect this change also occurred in between. <br>
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But I certainly don't know that's the case, or exactly why. Perhaps someone else will chime in.<br>
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-Greg<br>
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<span style=" font-family:'times new roman'; font-size: 11pt; color: #1f497d;"> Thanks Greg and Simon. Things I didn’t find when searching.<br>
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Yes we run failover. My question was really: Was this added between 4.1.1 and 4.2.5 ?<br>
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I skimmed the release notes and couldn’t find it. My users noticed this after the migration from the 4.1.1 server to the 4.2.5 server, so I am thinking the answer is yes. And I want to explain why it wasn’t happening before but is now.<br>
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<span style=" color: #17365d;"><b>Don Friesen<br>
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<span style=" font-size: 10pt; color: #000000;">From:</span></b><span style=" font-size: 10pt; color: #000000;"> <a href="mailto:dhcp-users-bounces@lists.isc.org">dhcp-users-bounces@lists.isc.org</a> [<a href="mailto:dhcp-users-bounces@lists.isc.org">mailto:dhcp-users-bounces@lists.isc.org</a>] <b>On Behalf Of </b>Gregory Sloop<br>
<b>Sent:</b> Monday, October 26, 2015 7:22 AM<br>
<b>To:</b> 'Users of ISC DHCP'<br>
<b>Subject:</b> Re: 20 minute leases<br>
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<span style=" font-size: 9pt;">This sounds like a fail-over setup, where clients get the MCLT time for the initial lease and then the full lease value after a renewal. This is so that the fail-over servers can communicate and properly handle the client.<br>
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[Glenn had a great post I found that explains more about fail-over, MCLT and initial lease times.]<br>
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</span></span></span></span><a style=" font-family:'times new roman'; font-size: 9pt;" href="https://lists.isc.org/pipermail/dhcp-users/2015-February/018578.html">https://lists.isc.org/pipermail/dhcp-users/2015-February/018578.html</a> <br>
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<span style=" font-family:'times new roman'; font-size: 9pt;">HTH<br>
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-Greg<br>
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<span style=" font-family:'times new roman'; font-size: 11pt;"> Hopefully a quick question. We migrated some sites from a few old DHCP servers running 4.1.1 to some not as old servers running 4.2.5. The users with laptops began complaining about sporadic loss of IP connectivity. They noticed they were getting 20 minutes leases instead of 24 hour leases. I watched the traffic and it seems all initial leases to unknown MAC addresses get a 20 minute lease and on renewal get the 24 hour lease. This is not a complaint, I like the idea of a trial lease. I just want to verify that the 4.1.1 version did not have this behavior without having to recreate that environment. I’d like to explain the behaviour to my users with a degree of confidence.<br>
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<span style=" font-size: 10pt; color: #002060;"><b>Don Friesen</b></span></span></td>
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<span style=" font-family:'arial'; color: #c0c0c0;"><i>-- <br>
Gregory Sloop, Principal: Sloop Network & Computer Consulting<br>
Voice: 503.251.0452 x82<br>
EMail: </i></span><a style=" font-family:'arial';" href="mailto:gregs@sloop.net">gregs@sloop.net</a><br>
<a style=" font-family:'arial';" href="http://www.sloop.net">http://www.sloop.net</a><br>
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