DHCP reconnection and renewal

flypanda999

First question: all kinds of information on the Internet says that after getting IP through DHCP, login again without sending DHCP discover packet, send DHCP request packet directly, and request to count down again. But whether it‘s Pt or dns3, after I save it, the whole topology will restart, and the discovery will start all over again - DHCP client sends DHCP discover. Excuse me, did I do it wrong? How to simulate the login of DHCP client.
The second question: in GNS3, the DHCP server configures a one minute lease period to observe the renewal. Then it suddenly breaks the connection between the client and the server. The packet capture shows that the client sends four requests, but there is no response. After a while, it starts sending DHCP discovery in a second interval. It has been waiting for a long time, and the client‘s address has always been the same as the previous address obtained through DHCP. Is it a bug or just like this in reality