subnetting my coffee shop

About this video

A hands-on subnetting lesson on subnetting by host requirements rather than by number of networks. The scenario is to split 10.1.1.0/24 across three coffee shops, each needing about 40 hosts (five employees, one server, two Raspberry Pis, two wireless access points, and up to 20 guests, plus wiggle room). Using the creator’s ‘Nora 2’ chart, 40 hosts require the next size up, 64 addresses, which takes six bits — so six host bits are reserved from the right, the reverse of the network-requirements method, and the remaining host bits become network bits. The increment is 64, giving three /26 networks: 10.1.1.0, 10.1.1.64, and 10.1.1.128, each with 62 usable addresses after the network and broadcast addresses. Converting the mask gives 255.255.255.192, i.e. slash 26, found by counting network bits and adding the on-bits 128 plus 64. A sponsored segment covers IP Royal proxies for web scraping and anonymity. A second practice example has an ISP carving a slash 16 network for five customers needing at least 20 static IPs each: 32 addresses fit the need, five host bits are reserved, the increment is 32, and the result is slash 27 networks with 30 usable addresses each, conserving address space. The video closes by previewing reverse-engineering a broadcast address from a host IP and slash 21 mask.

Key takeaways

• Subnetting by hosts flips the method: reserve the needed host bits from the right instead of borrowing from the left
• 40 hosts need 64 addresses, so reserve 6 host bits, giving an increment of 64
• The coffee-shop split yields three /26 networks (255.255.255.192) with 62 usable addresses each
• Usable addresses exclude the network address (first) and broadcast address (last) in each subnet
• ISP example: 20+ IPs need 32 addresses, 5 host bits, increment 32, producing /27 networks with 30 usable each

Episode details: published May 19, 2023 · 14:31 long. Summary written by Self Growth Videos from the episode itself. Business results and any income figures mentioned are NetworkChuck’s own claims, shared for education — they are not typical or guaranteed.

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