Question

1as a dhcpv4 client lease is about to expire, what is the message that the client sends the dhcp server?

Answer 1

The message sent here is ' broadcast DHCPREQUEST '.  In this case, before the period expires, IP configuration should be renewed. After this, IP address renewal process starts. If the lease expires and is not renewed, then the process of lease generation begins. If DHCP is available, then lease is renewed, even when fifty percent of it expires.