dhcp-client and IPv4 lease times

[Mike]

I'm running dhcp-client-4.4.2.P1 from packages on OpenBSD 7.0, amd64..

The IPv4 lease renewal times seem odd to me.

>From the environment passed to the script specified in dhclient4.conf, I
see, among others, the following variables:

new_dhcp_lease_time=45605
new_dhcp_rebinding_time=34805
new_dhcp_renewal_time=2405


In the log for the dhclient daemon I see the following entry (sanitized):

dhclient: ... -- renewal in 2121 seconds.


I have two questions:

1) Why is the renewal time specified in the log different than any of
the renewal times passed in the environment?

2) Why is not the renewal time taken to be half the lease time?

Thanks.