Latest lease entry not the one offered to the client

[Klemen Sladic]

Hi.

I did not manage to find any related discussion, so I'd like to ask this:

Using ISC DHCP 4.3.5 server and client.
DHCP server has these two entries in its dhcpd.leases (first lease at line
106, second at line 205):

lease 1.1.1.17 {
  starts 4 2020/08/13 00:40:24;
  ends 0 2020/08/23 00:40:24;
  tstp 0 2020/08/23 00:40:24;
  cltt 4 2020/08/13 00:40:24;
  binding state active;
  next binding state free;
  rewind binding state free;
  hardware ethernet 00:0d:ca:00:0f:dd;
  set lease_mac = "0:d:ca:0:f:dd";
}
lease 1.1.1.28 {
  starts 4 2020/08/13 03:03:13;
  ends 0 2020/08/23 03:03:13;
  tstp 0 2020/08/23 03:03:13;
  cltt 4 2020/08/13 03:03:13;
  binding state active;
  next binding state free;
  rewind binding state free;
  hardware ethernet 00:0d:ca:00:0f:dd;
  set lease_mac = "0:d:ca:0:f:dd";
}

This made me think that 1.1.1.28 is the newest lease and should be the
valid one for the client.
But if I do renew on the client it is being offered 1.1.1.17 (timestamps
are in different zone, port is custom):

Aug 13 21:10:39 (none) daemon.info
<https://slack-redir.net/link?url=http%3A%2F%2Fdaemon.info&v=3> dhclient:
DHCPREQUEST on eth0 to 255.255.255.255 port 17787
Aug 13 21:10:39 (none) daemon.info
<https://slack-redir.net/link?url=http%3A%2F%2Fdaemon.info&v=3> dhclient:
DHCPACK from 1.1.1.1
Aug 13 21:10:41 (none) daemon.info
<https://slack-redir.net/link?url=http%3A%2F%2Fdaemon.info&v=3> dhclient:
bound to 1.1.1.17 -- renewal in 392208 seconds.

Since some of my applications rely on knowing valid DHCP client IPs, this
is a problem.

I'd like to ask if that is a known issue or there may be something related
to my network or DHCP config?
Am I misinterpreting the dhcpd.leases file? I thought DHCP server appends
most recent leases at the end?

Thank you very much any help is much appreciated.

RegK
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