The layers in the TCP$/$IP protocol suite are shown in Figure $3.$

Figure $3$: TCP$/$IP Protocol Suite

a$)$ If we were to add a security layer immediately above the physical layer. How would we do it$?$ Discuss

the type of addresses and the level of authentication that could be provided by doing this.

b$)$ What would be the advantages of providing security immediately above the physical layer.

c$)$ What would be the dis$-$advantages of providing security immediately above the physical layer.

d$)$ Provide an example scenario where adding security immediately above the physical layer would make

sense.