Consider the following network consisting of three three$-$station Ethernets attached via an IP router.

Hosts A through L have MAC addresses of aaa, bbb$,$ ccc$,$ ddd$,$ eee, fff$,$ ggg$,$ hhh$,$ iii, jjj$,$ kkk$,$ and lll

respectively. Router port $1$ has MAC address xxx$,$ port $2$ has MAC address yyy$,$ and port $3$ has MAC

address zzz$.$ The Switch has three interfaces with MAC address sssaaa, sssbbb$,$ and sssccc$.$ The host id

is shown above each host, the net$-$id below the Ethernet.

a$.$ Give the ARP cache $($table$)$ for station F assuming that F has recently communicated with

stations H$,$ D$,$ E$,$ A and K only.

$001$

A

$002$

B

$003$

C

$001\mathrm{.}128\mathrm{.}123$

$004$

D

$005$

E

$006$

F

$001\mathrm{.}128\mathrm{.}124$

$123$

Router

$007$

G

$008$

H

$009$

I

$001\mathrm{.}128\mathrm{.}125$

$012$

L

$011$

K

$010$

J

$001\mathrm{.}128\mathrm{.}125$

Switch

sssaaa

sssbbb sssccc

$6$

ECE $4436$a Final December $18,2013$

b$.$ Give the switching table of the switch assuming that in the last $20$ minutes: $1)$ A has

communicated with B; $2)$ F has communicated with stations H$,$ D$,$ E$,$ A and K; $3)$ L has

communicated with I and C$.$

c$.$ Give the routing table for the router.

d$.$ If A sends K a packet, explain what takes place. Assume no activity has been reported in the

last hour.