In Figure $6\mathrm{.}5,$ do we have a loop problem if we change the hub in one of the

LANs to a link$-$layer switch?

PR$-3.$ In Figure $6\mathrm{.}5,$ do we have a loop problem if we change each hub in the

LANs to a link$-$layer switch?

PR$-4.$ Does each port of the switch in Figure $6\mathrm{.}5$ need a link$-$layer address?

Explain.

PR$-5.$ If the switch is connected to a router to provide access to the Internet, does

it need a link$-$layer address? Explain.