Type each command and press Enter. Abbreviations welcome — conf t, int gi0/1, sw mo tr.
Calculate a subnet, convert binary by hand, and study the reference tables.
Binary 00000000 = Decimal 0
32-bit binary
=
Enter an IP and prefix. The network bits (mask = 1) are kept; the host bits (mask = 0) become 0 — that gives the network number.
Binary
Decimal
Given a network and a requirement, find the prefix: 2ˣ − 2 ≥ hosts needed; 2ˢ ≥ subnets needed.
List each subnet's host need. The planner sizes each (largest first) and lays them out from the base block with no overlap.
Split a network into equal subnets and read off any subnet's network, usable range, and broadcast — e.g. “first usable in the 3rd subnet?”