DHCP server offers same lease regardless of changed option

[Klemen Sladic]

Hi.

I have a question regarding valid leases.
Let's say DHCP server is configured with a host entry using a custom DHCP
option with some predefined value, like:

host host1 {
hardware ethernet 00:01:02:03:04:05;
option my-net-opt "host1_net_opt"; }

After host1 gets this lease and recognizes the option the lease is valid
for (let's say) 10 days.

Now I reconfigure DHCP server by changing option value for that host, like:

host host1 {
hardware ethernet 00:01:02:03:04:05;
option my-net-opt "host1_net_opt_new"; }

and restart the DHCP server.

What I am experiencing is that if host1 requests a new lease (after restart
or renew) while the old one is still valid, it gets the same old lease with
the old option value.

My questions are:
1. Is this expected behaviour or am I doing something wrong?
2. If this is how it works is there a way to somehow invalidate that old
lease to force the server to create a new one with a new option value?

Thank you very much.
Any help would be highly appreciated.

RegK