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<div class="">In the previous example, e8802ea2eb7f (an Apple device) is requesting<br class="">
10.45.13.196. One server, landlord02, is erroneously stating that the<br class="">
client hostname is android-9375f90cad51e32f. It turns out that, a few<br class="">
days ago, landlord02 offered this IP address to an Android device with<br class="">
the hostname of android-9375f90cad51e32f. Looking at the source code,<br class="">
it appears that dhcpd is not reporting the hostname found in the<br class="">
packet, but rather, the information collected from its lease file.<br class="">
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<div>Norman, since we see the REQUEST relayed by your router, it’s a broadcast REQUEST. I’m assuming this is part of the initial broadcast DISCOVER - OFFER - REQUEST - ACK sequence, and not a later REQUEST being broadcast? (That can happen but only under
special circumstances.)</div>
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<div class="">I speculate that this happened:</div>
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<div class="">1. The client did a broadcast DISCOVER that was relayed to both servers. Possibly both of them logged the correct client-hostname in their DISCOVER messages.</div>
<div class="">2. Both servers sent OFFERs back toward the client via the relay. landlord01’s OFFER was for 10.45.13.196 ; landlord02’s OFFER was for some other IP.</div>
<div class="">3. The client decided to accept landlord01’s offer and broadcast a REQUEST for that offer.</div>
<div class="">4. landlord01 received the REQUEST and logged it correctly.</div>
<div class="">5. landlord02 received the REQUEST and, recognizing that it was in response to an OFFER made by its peer, logged it without inspecting the packet for current supplemental data, leaving in place the cached client-hostname from the last client
to hold this lease (IP) when offered by landlord02.</div>
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<div class="">That is to say, client-hostname tends to stay cached a long time, misleadingly, in the lease database of the peer of the server that’s handling the client currently holding that lease / IP.</div>
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<div class="">That’s … more difficult to phrase than I expected it to be. Perhaps there’s an easier way to describe it.</div>
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<div style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-position: normal; font-variant-caps: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
<span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: normal; border-spacing: 0px; -webkit-text-decorations-in-effect: none;">
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<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-position: normal; font-variant-caps: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; border-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-stroke-width: 0px;">
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<span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-position: normal; font-variant-caps: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px;">
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<div class="">-- </div>
<div class="">Keith Neufeld</div>
<div class="">Director of Networking, Telecommunications, and IT Security</div>
<div class=""><span style="text-align: -webkit-auto;" class="">Wichita State University</span></div>
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