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</style></head><body><p style="font-size:11pt;">I've got a pretty weird situation here.</p><p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">I have some Canon MFC's (MF1643i, if it matters)</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">We have a half a dozen or so.</p>
<p style="font-size:11pt;">They have a pretty odd relationship with the DHCP servers.</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">They'll get an IP fine, and stay up for days, but then suddenly they'll simply fail to renew the IP and get a 169 address. There's a setting in the network control panel to turn off "Auto IP" which appears to be a "feature" that might do this.</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">I've turned it off on a few, but I can't tell if that's fixed anything - since it only happens occasionally.</p>
<p style="font-size:11pt;"> </p>
<p style="font-size:11pt;">But that's not the real question. I only mention this because it might have bearing on another issue.</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">Along with the DHCP reservation (via a class statement that puts these printers in a specific pool/address-space) - I also have dhcpd creating DDNS records for them. We point print clients at the FQDN of the printer. </p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">(I won't get into why we like having the printers on DHCP, but there are some nice advantages.)</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">However, what I'm seeing now is that the printer will renew the lease at the 50% mark, and in the logs I see it request and ACK the lease renewal, but then there's an immediate DDNS forward map removal.</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">Here's some lightly sanitized logs. (The logs are from the syslog server, so you're seeing logs from both DHCP servers, not just one; we run a failover/balance DHCP pair.)</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">You can see the "start" of one of these events. The forward map is removed. </p><p style="font-size:11pt;">(And obviously, if we're printing to this printer with the FQDN this because a big problem.)</p>
<p style="font-size:11pt;"> </p><p style="font-size:11pt;">I have a monitor on this printer currently, so I notice it went down, and can't do name resolution.</p>
<p style="font-size:11pt;">It's still got an IP and I can still talk to it via the IP.</p>
<p style="font-size:11pt;">So, I simply force the printer to re-start.</p>
<p style="font-size:11pt;">AFAICT, DHCP still thinks it's got an active lease. (Born out my the reuse_lease message.)</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">It goes about doing a discovery gets an offer ACKS the lease, and re-creates the forward map for my FQDN.</p>
<p style="font-size:11pt;">The lease is 8H, BTW.</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">So, at 4H it renews, but then for some reason DHCPD removes the forward again. (Though DHCP shouldn't remove the forward until the client explicitly releases the lease, or fails to renew in 8H.)</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">Jun 24 13:46:27 my-dns-dhcp-2 dhcpd[721]: Removed forward map from my-scanner-scan.mydom.local to 10.8.28.83</p>
<p style="font-size:11pt;">Jun 24 13:57:56 my-dns-dhcp-1 dhcpd[13147]: DHCPDISCOVER from 74:bf:c0:11:22:33 (my-scanner-scan) via 10.8.28.1: load balance to peer dhcp-failover</p>
<p style="font-size:11pt;">Jun 24 13:57:56 my-dns-dhcp-2 dhcpd[721]: reuse_lease: lease age 689 (secs) under 25% threshold, reply with unaltered, existing lease for 10.8.28.83</p>
<p style="font-size:11pt;">Jun 24 13:57:56 my-dns-dhcp-2 dhcpd[721]: DHCPDISCOVER from 74:bf:c0:11:22:33 via 10.8.28.1</p>
<p style="font-size:11pt;">Jun 24 13:57:57 my-dns-dhcp-2 dhcpd[721]: DHCPOFFER on 10.8.28.83 to 74:bf:c0:11:22:33 via 10.8.28.1</p>
<p style="font-size:11pt;">Jun 24 13:57:57 my-dns-dhcp-1 dhcpd[13147]: DHCPREQUEST for 10.8.28.83 (10.8.20.6) from 74:bf:c0:11:22:33 (my-scanner-scan) via 10.8.28.1</p>
<p style="font-size:11pt;">Jun 24 13:57:57 my-dns-dhcp-1 dhcpd[13147]: DHCPACK on 10.8.28.83 to 74:bf:c0:11:22:33 (my-scanner-scan) via 10.8.28.1</p>
<p style="font-size:11pt;">Jun 24 13:57:57 my-dns-dhcp-2 dhcpd[721]: DHCPREQUEST for 10.8.28.83 (10.8.20.6) from 74:bf:c0:11:22:33 via 10.8.28.1</p>
<p style="font-size:11pt;">Jun 24 13:57:57 my-dns-dhcp-2 dhcpd[721]: DHCPACK on 10.8.28.83 to 74:bf:c0:11:22:33 (my-scanner-scan) via 10.8.28.1</p>
<p style="font-size:11pt;">Jun 24 13:57:57 my-dns-dhcp-2 dhcpd[721]: bind update on 10.8.28.83 from dhcp-failover rejected: incoming update is less critical than outgoing update</p>
<p style="font-size:11pt;">Jun 24 13:57:57 my-dns-dhcp-1 dhcpd[13147]: Added new forward map from my-scanner-scan.mydom.local to 10.8.28.83</p>
<p style="font-size:11pt;">Jun 24 13:57:57 my-dns-dhcp-2 dhcpd[721]: Added new forward map from my-scanner-scan.mydom.local to 10.8.28.83</p>
<p style="font-size:11pt;">Jun 24 17:57:57 my-dns-dhcp-2 dhcpd[721]: DHCPREQUEST for 10.8.28.83 from 74:bf:c0:11:22:33 (my-scanner-scan) via eth1</p>
<p style="font-size:11pt;">Jun 24 17:57:57 my-dns-dhcp-2 dhcpd[721]: DHCPACK on 10.8.28.83 to 74:bf:c0:11:22:33 via eth1</p>
<p style="font-size:11pt;">Jun 24 17:57:57 my-dns-dhcp-2 dhcpd[721]: Removed forward map from my-scanner-scan.mydom.local to 10.8.28.83</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">---</p>
<p style="font-size:11pt;">Since this isn't happening for any other clients in the network, and no other make/model of printers, I assume the printer must be doing something that provokes it. But I have no idea how to stop it, what's wrong etc.</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">And it doesn't happen all the time for all these Canon printers. Just some, some of the time.</p>
<p style="font-size:11pt;">Gak!</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">Yeah, probably packet caps are the best option, but when it's sporadic, that's kind of hard to do.</p>
<p style="font-size:11pt;">I guess I'm here asking "Has anyone seen anything like this, before? And if so, what kinds of things might be the culprit."</p>
<p style="font-size:11pt;"><br/></p>
<p style="font-size:11pt;">[Hey, at least it accepts a lease < 1Y, eh Simon!?! :) ]</p><p style="font-size:11pt;"> </p><p style="font-size:11pt;">TIA</p><p style="font-size:11pt;">-Greg</p><p style="font-size:11pt;"> </p></body>