SUBNET PRACTICE_
Enter an IP/CIDR or hit random. Solve the network, hosts, broadcast, and adjacent subnets. Each field is graded independently.
[ ▶ QUICK SUMMARY ]
This free, browser-based subnetting drill generates random IPv4 address + CIDR problems and grades each field independently. For any IP/prefix you find the network address (host bits all 0), the broadcast address (host bits all 1), the first and last usable hosts, and the adjacent subnets. Usable hosts in a /n = 2^(32−n) − 2. No signup — practice until it's automatic.✗ Invalid. Use dotted-decimal with prefix — e.g. 10.0.1.50/24
[ GIVEN ADDRESS ]
—
NETWORK ADDRESS
FIRST HOST
LAST HOST
BROADCAST
NEXT SUBNET
PREVIOUS SUBNET
0/0
[ ★ KEEP THE MOMENTUM ]
You just graded a drill. Want the printable /8–/32 cheat sheet and new labs the moment they drop? Grab it free below — or run today's CCNA practice questions to start a streak.
[ ★ NEED A REFERENCE? ]
Every prefix /8 through /32 — subnet mask, block size, usable hosts, and wildcard mask — in one page you can save or bookmark.
CIDR CHEAT SHEET ▶
[ ★ APPLY IT IN A REAL TOPOLOGY ]
Subnetting makes more sense when you're actually assigning addresses to interfaces. Put your skills to work in a real network — VLANs, inter-VLAN routing, and more._