Use Figure $1$ ?as a reference, if the values are A$,$ ?B$,$ ?C and D $($in the $3$rd octet$)$ ?with the following conditions:

Grade A $=$ ?the sum of the last $5$ ?digits of your NIM$($so i will be $77404)$

Grade B$=$ ?A $+3$

Grade C$=$B $+5$

Grade D$=$C $+7$

$?$ ?D$1,$ ?E$1,$ ?F$1$ ?are interfaces for the gateway router, while D$2,$ ?D$3,$ ?E$2,$ ?E$3,$ ?F$2,$ ?F$3$ ?are interfaces for the router

a$.$ ?How many networks $($LANs$)$ ?are there in the picture?

b$.$ ?Determine the Routing Table for R$1,$ ?R$2,$ ?and R$3$ ?using the following table!

?$|-------------------------------|$

$|$ ? Destination $|$ ? Next hop $|$ ? Interface $|$

$|-------------------------------|$

$||||$

$|-------------------------------|$

c$.$ ?Using the Routing Table that you have specified in point b$,$ ?write down which path the ICMP packets $($Echo and Echo reply$)$ ?will take if you run the PING command from PC$1$ ?to PC$4$ ?and from PC$1$ ?to PC$6$

d$.$ ?State the network address for each network according to the number you mentioned in point a above

PC4 192.168.8.120/24 PC3 192.168 B 125/24 PC1 192.168.A.5/24 PC2 192.168 A 10/24 Switch 1 Switch 2 D1 192.168 A 1/24 E1 *192.168.B.1/24 R1 E2 10.2008.5/28 02 10 200 B. 10/28 D3 10.10.8.190/28 R2 E3 10.21.8.6:30 F2 10:21.8.6/30 F3 10.10.8.200/28 R3 F1 192.168 C 1/24 Switch PC6 192.168.C.16/24 PC5 192.168 C 18/24