Question $1$: The following LAN comprises six computers interconnected by one self$-$learning Ethernet switch. Initially, at $t=0,$ the switch table is empty. At subsequent time intervals $t=1,2,3,4$ and $5,$ a source node transmits to a designated destination node, followed promptly by a reply from the destination. Given the transmissions listed below, consider the transmissions that occur in reply and complete the switch table accordingly with the interface. Provide the necessary explanation.

At $t=1,DF$

At $t=2,DB$

At $t=3,CD$

At $t=4,AE$

At $t=5,EF$