IP Subnetting Math: Binary, CIDR, Hosts & VLSM

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Split six octets into their 8 bits, write them as 8-digit binary with DEC2BIN, count their 1-bits and read binary octets back with BIN2DEC.
• Join octets into dotted addresses, turn Kestrel Freight's device addresses into one 32-bit integer and split integers back into octets with INT and MOD.
• Turn seven prefixes into subnet masks octet by octet, write the mask and wildcard as dotted text and count the 1-bits to get a prefix back from a mask.
• For four Kestrel Freight devices you calculate the block size, round the address down to its network, add the block for the broadcast and write the network address as dotted text, then confirm it with BITAND.
• Calculate usable hosts for /23 to /30, then size Kestrel Freight's six segments: host bits needed, the prefix and how full each subnet will be.
• Split Kestrel Freight's branch network 192.168.20.0/24 into equal subnets: bits borrowed, new prefix, block size and the network and broadcast of every subnet.
• Allocate Kestrel Freight's 192.168.30.0/24 to six segments of different sizes: host bits, prefix and block per segment, the running start offset, the network address of each subnet and the space left over.
• Read an IPv6 address group by group with HEX2DEC, count the /64 subnets in Kestrel Freight's /48 and chart how fast IPv4 usable hosts fall from /22 to /30.