Figure $1$ above shows two residential networks with routers that implement NAT.

$($a$)$ Suppose host $A$ is connected to the web server at host $E.$ Show the values of the

address and port fields in the diagram below, for a typical packet sent by host $A.$

$($b$)$ Show the fields in the packet as it might appear when it reaches $E.$

$($c$)$ Suppose the user in the right$-$hand network wants to run a web server on host D$.$ Add

one entry to the right$-$hand table that would allow remote connections to the web

server.

$(2$ Marks$)$

$($d$)$ Assume host B connects to the web server at D$.$ Add one entry to the left$-$hand NAT

table for this connection. Show the address and port field for a typical packet leaving

host $B$ to be delivered to $D.$