Figure $2$: Network topology for Problem $4.$

Problem $4(12$ points$)$: Consider three LANs interconnected by two routers, as shown in Fig. $2.$

$($a$)$ Consider sending an Ethernet frame from Host E to Host B$.$ Suppose all of the ARP tables are up to date. Enumerate all the steps that are needed for sending the frame.

$($b$)$ Repeat part $($a$),$ now assuming that the ARP table in the sending host is empty $($and the other tables are up$-$to$-$date$).$