Nick Howitt wrote:

Static IP's are not listed, but also do not show up in the leases or any dnsmasq-dhcp negotiation logs.

The static leases are also listed in DHCP list.
These devices had receipt the IP from the DHCP server and are set as static in the menu later.

Nick Howitt wrote:

So the lease we were talking about has expired, but did it renew more recently (within the 12h window)?

Yes. The devices is connect for a few month and is getting its IP renew everytime

Static IP's are not listed, but also do not show up in the leases or any dnsmasq-dhcp negotiation logs.

Has the device a static IP address? I'm not completely sure but I think when the address is static it is not listed in your DHCP list.

So the lease we were talking about has expired, but did it renew more recently (within the 12h window)?

Nick Howitt wrote:

What is your default lease time (in the DHCP Server settings)? Do you have anything in the dnsmasq.leases file or /etc/ethers (static leases)?

Lease time is 12H


/etc/ethers

# This is an auto-generated file. Please do NOT edit

# Comments are used to aid in maintaining your hosts

# file

dc:ef:ca:a3:f7:90 192.168.1.200

ec:8e:b5:26:28:bb 192.168.1.230

b0:b9:8a:54:3e:e8 192.168.1.220

70:10:6f:3e:41:96 192.168.1.150

a4:5d:36:91:e4:70 192.168.1.210

dnsmasq.leases

1568053777 00:04:20:22:22:70 192.168.1.201 SqueezeboxTouch 01:00:04:20:22:22:70

1568031020 58:b0:d4:47:47:39 192.168.1.234 * 01:58:b0:d4:47:47:39

1568047174 00:04:20:26:23:70 192.168.1.100 SqueezeboxRadio 01:00:04:20:26:23:70

1568048755 88:71:b1:65:f8:9a 192.168.1.158 Mediabox 01:88:71:b1:65:f8:9a

1568050513 20:78:f0:cd:76:cc 192.168.1.225 AppleWavanLinda 01:20:78:f0:cd:76:cc

1568049886 dc:ef:ca:a3:f7:90 192.168.1.200 qb-659916001600-1801A016PB *

1568030644 4c:74:bf:d9:d0:25 192.168.1.191 iPhone-Patrick 01:4c:74:bf:d9:d0:25

1568042759 24:f0:94:1c:90:b1 192.168.1.163 iPhone-Jordy 01:24:f0:94:1c:90:b1

1568054845 a4:5d:36:91:e4:70 192.168.1.210 * *

1568067202 b0:b9:8a:54:3e:e8 192.168.1.220 * *

1568057297 70:10:6f:3e:41:96 192.168.1.150 ilo *

1568064821 0c:3e:9f:f2:81:3d 192.168.1.117 iPad-Patrick 01:0c:3e:9f:f2:81:3d

1568037768 58:40:4e:bd:b0:4f 192.168.1.195 Iphone-Linda 01:58:40:4e:bd:b0:4f

1568060980 ec:8e:b5:26:28:bb 192.168.1.230 NPI2628BB *

1568051197 88:66:a5:ce:1b:da 192.168.1.116 iPhone-Thomas 01:88:66:a5:ce:1b:da

IP 192.168.1.208 is missing in the lists.

What is your default lease time (in the DHCP Server settings)? Do you have anything in the dnsmasq.leases file or /etc/ethers (static leases)?

Same. This IP is also missing.
I've added on advise of Dave "dhcp-leasefile=/var/lib/dnsmasq/dnsmasq.leases" in /etc/dnsmasq.conf, but no change.

(https://www.clearos.com/clearfoundation/social/community/nothing-in-dhcp-server-leases-list#reply-59987)

So what is in /var/lib/dnsmasq/dnsmasq.leases?

This is apparently the case.

Sep  5 22:28:16 dnsmasq-dhcp[13780]: DHCPDISCOVER(eno2) 00:27:02:1c:6f:64

Sep  5 22:28:16 dnsmasq-dhcp[13780]: DHCPOFFER(eno2) 192.168.1.208 00:27:02:1c:6f:64

Sep  5 22:28:16 dnsmasq-dhcp[13780]: DHCPDISCOVER(eno2) 00:27:02:1c:6f:64

Sep  5 22:28:16 dnsmasq-dhcp[13780]: DHCPOFFER(eno2) 192.168.1.208 00:27:02:1c:6f:64

Sep  5 22:28:16 dnsmasq-dhcp[13780]: DHCPREQUEST(eno2) 192.168.1.208 00:27:02:1c:6f:64

Sep  5 22:28:16 dnsmasq-dhcp[13780]: DHCPACK(eno2) 192.168.1.208 00:27:02:1c:6f:64 target

You should have an ACK with the OFFER. The ACK is a message from the client device that it has received the OFFER and accepted it. For example:

Sep 6 05:32:41 www1 dnsmasq-dhcp[2877]: DHCPDISCOVER(enp2s0f1) d4:63:f6:46:f8:72
Sep 6 05:32:41 www1 dnsmasq-dhcp[2877]: DHCPOFFER(enp2s0f1) 10.2.3.164 d4:63:f6:46:f8:72
Sep 6 05:32:41 www1 dnsmasq-dhcp[2877]: DHCPREQUEST(enp2s0f1) 10.2.3.164 d4:63:f6:46:f8:72
Sep 6 05:32:41 www1 dnsmasq-dhcp[2877]: DHCPACK(enp2s0f1) 10.2.3.164 d4:63:f6:46:f8:72

Once the ACK is received, it will be listed in the database.