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<pre class="moz-quote-pre" wrap="">On 24-06-2019 02:38, A C wrote:
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<pre class="moz-quote-pre" wrap="">On 2019-06-23 11:08, Geert Stappers wrote:
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<pre class="moz-quote-pre" wrap="">On Sun, Jun 23, 2019 at 09:33:21AM -0700, A C wrote:
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<pre class="moz-quote-pre" wrap="">On 2019-06-23 03:32, Geert Stappers wrote:
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<pre class="moz-quote-pre" wrap="">On 23-06-2019 08:06, A C wrote:
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<pre class="moz-quote-pre" wrap="">I'm having trouble removing leases from my system.
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<pre class="moz-quote-pre" wrap="">I have:
/etc/dnsmasq.conf:
read-ethers ###(there is a dash)
dhcp-range=10.0.200.100,10.0.200.105,255.255.0.0,12h
### My netmask is actually 255.255.0.0 on the network, all dhcp leases
are in 10.0.200.x, static assignments are in other subnets
/etc/ethers:
00:25:9C:1C:0A:C3 ap.lan
### and others
/etc/hosts:
10.0.0.252 ap.lan
### and others
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<pre class="moz-quote-pre" wrap="">How can I fully purge the lease and get it to start over? The client is
an embedded device and has no memory of the lease once I power cycle it
so somehow dnsmasq is remembering even though the lease file was purged.
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<pre class="moz-quote-pre" wrap="">Recently I had simular sympthoms, infact still have them.
My only issue is when I forget to add a client to the list
prior to first putting it online and it acquires a lease from the DHCP
lease pool instead of the IP I want to give it via the combination of
ethers/hosts. After that I have extreme difficulty purging the lease to
force a new address.
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<pre class="moz-quote-pre" wrap="">My /etc/ethers has a line like
00:02:b0:ef:f0:ef kornuit
Doing `host kornuit` returns correctly the IPv4 address that is in DNS.
(other DNS as dnsmasq ( no kornuit entry in /etc/hosts ))
I also stopped dnsmasq, removed the lease file and restarted dnsmasq.
Did another PXE netboot ( consider it an embedded device, it has no
memory of previous lease )
Server kornuit got the IPv4 address as before, one from the Dnsmasq
DHCP range. Where it looks like a persistent DHCP lease, do I think
that it is algoritme that hands out each time the same IPv4 address.
Thing I need to verify is if dnsmasq does do a DNS-lookup on 'kornuit'
after reading /etc/ethers.
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<pre class="moz-quote-pre" wrap="">Now using `dhcp-host=MA:CA:DD:RE:SS,192.0.2.42
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<pre class="moz-quote-pre" wrap="">host ap.lan localhost (run on the same server as dnsmasq) returns
10.0.0.252 as expected.
Turned off the device, stopped dnsmasq, removed the lease from the lease
file, restarted dnsmasq and then restarted the device. I get the old
DHCP range lease instead of the one defined in hosts.
If I add a host entry (with an IP outside of the DHCP range) and an
ethers entry for a device bore I ever plug it into the network I will
correctly get a static lease of the IP I define in hosts. If I forget
to do that, the device picks up a lease from the DHCP range and then
it's a massive fight to get rid of it. Sometimes I have to leave the
device disconnected for a few days so the lease expires on its own
(regardless of deleting the lease) and then I can switch the IP.
There seems to be some kind of persistence that exists outside of just
the lease file but I don't know where that is. This isn't the first
time this has happened and it's happened with different embedded devices
and non-embedded devices (cameras, AP's, IoTs, phones, etc.) there just
seems to be sticky lease data somewhere.
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<pre class="moz-quote-pre" wrap="">You are probadly right about the "sticky lease data somewhere"
(I'm not comfortable to say "you are right about sticky lease data" )
The lease file I removed had size of zero bytes.
My (educated??) guess is that lease data is stored in Dbus.
My only point to back that up, is `dnsmasq -v` showing "DBus"
Cheers
Geert Stappers
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