Condensed notes, live subnetting/address-table builders, and a mixed practice paper — Topics 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12.
Condensed from your Topic 5, 6, 7, 9, 10, 11 and 12 slide decks. Skim these first, then go do the calculators — you learn subnetting by doing it, not reading it.
Type any IP + prefix. This shows you exactly how the network address, broadcast, and usable host range are calculated — the same steps you must show working for in the exam.
Give a base network, then say how many subnets you need (or how many hosts each one must hold). This borrows host bits and lists every resulting subnet — exactly like Topic 9's "subnet within an octet boundary" tables.
This is the real exam skill from Topic 10: given a base network and a list of LANs/WAN links with different host counts, build a full VLSM address table with zero wasted addresses. Largest requirement is always allocated first.
Write down every LAN and every point-to-point WAN link that needs an address block, with the number of usable hosts each one needs. WAN links between two routers always need exactly 2 hosts.
Always allocate the biggest host requirement first. This is the golden rule of VLSM — if you allocate small blocks first, you fragment the space and can't fit the big ones later.
For N hosts needed, find the smallest power of 2 that is ≥ N + 2 (network + broadcast address are reserved). That gives you the block size, and 32 − log2(block size) gives you the prefix.
The network address of each block must be a multiple of its own block size (e.g. a /29 block of 8 addresses must start at a multiple of 8). The calculator above snaps each block to the next valid boundary automatically.
Move the cursor to the end of the block you just placed, and repeat from Step 3 for the next-largest requirement, until every row has an address.
Practice the two compression rules: (1) omit leading zeros in each hextet, (2) replace the single longest run of consecutive all-zero hextets with :: — only once per address.
| Address type | Range / Prefix | Purpose |
|---|---|---|
| Global Unicast (GUA) | 2000::/3 | Globally routable, like a public IPv4 address |
| Unique Local (ULA) | fc00::/7 | Private/internal use, not globally routed |
| Link-Local (LLA) | fe80::/10 | Auto-created on every interface, never routed off the link |
| Multicast | ff00::/8 | One packet → many destinations |
| All-nodes multicast | ff02::1 | Every IPv6 device on the link |
| All-routers multicast | ff02::2 | Every IPv6 router on the link |
Covers Topics 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12. Answer everything then hit Grade My Test at the bottom — correct/incorrect is highlighted with a short explanation for each question.