Question

(/25) 11111111.11111111.11111111.10000000 dotted decimal subnet mask equivalent: ________________________________ number of subnets? ________________, number of hosts? ________________ (/26) 11111111.11111111.11111111.11000000 dotted decimal subnet mask equivalent: ________________________________ number of subnets? ________________, number of hosts? ________________ (/27) 11111111.11111111.11111111.11100000 dotted decimal subnet mask equivalent: ________________________________ number of subnets? ________________ number of hosts? ________________ (/28) 11111111.11111111.11111111.11110000 dotted decimal subnet mask equivalent: ________________________________ number of subnets? ________________ number of hosts? _________________ (/29) 11111111.11111111.11111111.11111000 dotted decimal subnet mask equivalent: ____

Answer 1

Count the number of 1 bits after the last decimal point. Call this number n.

There will be 2^n subnets and 2^(8-n) - 2 hosts per subnet. (You can mutilply the number of subnets by the number of hosts per subnet to find the total number of hosts.)

/25: 255.255.255.128, 2 subnets, 126 hosts per subnet

/26: 255.255.255.192, 4 subnets, 62 hosts per subnet

/27: 255.255.255.224, 8 subnets, 30 hosts per subnet

/28: 255.255.255.240, 16 subnets, 14 hosts per subnet

/29: 255.255.255.248, 32 subnets, 6 hosts per subnet