Consider the network shown in Figure $2.$ For this network, assume that a browser on host A$1$ with IP address $192\mathrm{.}168\mathrm{.}1\mathrm{.}220/24$ is communicating with a web server on host W with IP address $130\mathrm{.}215\mathrm{.}10\mathrm{.}11/16.$ The identifying parameters for various interfaces $($IP and Mac addresses$)$ are shown in Figure $2.$ Also assume that the WiFi router and the PON Box in the home network are collocated in a single middle box.

a$.$ The web server W receives a packet from the browser at client A$1.$ Show the addressing $($source$/$destination$)$ information at the Link $($MAC$)$ and Network Layers of the packet when it arrives at W and explain why they are those values.

b$.$ What is the routing protocol used between routers on Link A$?$ What is its purpose? At what layer does it operate?