VLSM guide

From ITCwiki
Jump to navigation Jump to search
CIDR/Default Subnet Mask Table
Class A Class B Class C
Binary (N/H) Decimal Block size Interesting Octet (2nd octet) (3rd octet) (4th octet)
00000000 = 0 256 /8 /16 /24
10000000 = 128 128 /9 /17 /25
11000000 = 192 64 /10 /18 /26
11100000 = 224 32 /11 /19 /27
11110000 = 240 16 /12 /20 /28
11111000 = 248 8 /13 /21 /29
11111100 = 252 4 /14 /22 /30
11111110 = 254 2 /15 /23
11111111 = 255 1