No. of host =1500 No. of host bits =[log21500]=11 bits ∴ Total possible hosts =211=23×28 n is the netmask bits, Range of addresses is =232−n 211=232−π Available IP address ⇒202.61.0.0/17
0000
0000.0000
0000
0000
0111.1111
1111
}0.0−7.255
0000
1000.0000
0000
0000
1111.1111
1111
}8.0to15.255
So the IP address follow the pattern 0.0 to 7.255 8.0 to 15.255 16.0 to 23.255 ⋮ 64.0 to ... ⋮ 104.0 to ... ∴ The possible IP addresses are 202.61.64.0/21 & 202.61.104.0/21