Consider three LANs interconnected by two routers, as shown in the figure below.

$($a$)(3$ points$)$ Assign IP addresses to all of the interfaces. For Subnet $1$ use addresses of the form

$192\mathrm{.}168\mathrm{.}1.$xxx; for Subnet $2$ uses addresses of the form

$192\mathrm{.}168\mathrm{.}2.$xxx; and for Subnet $3$ use addresses of the form

$192\mathrm{.}168\mathrm{.}3.$xxx$.$

$($b$)(3$ points$)$ Assign MAC addresses to all of the adapters.

$($c$)(3$ points$)$ Consider sending an IP datagram from Host E to Host B$.$ Suppose all of the ARP tables are up to date. Enumerate all the steps.

$($d$)(3$ points$)$ Now we replace the router between subnets $1$ and $2$ with a switch S$1,$ and label the router between subnets $2$ and $3$ as R$1.$

$($e$)(3$ points$)$ Consider sending an IP datagram from Host E to Host F$.$ Will Host E ask router R$1$ to help forward the datagram? Why?