# Host sizing, VLSM and aggregation

Subject: Computer Networks

Exam: M2

Reader: https://deep-learning-study-room.vercel.app/cn/#m2/formulas/formulas/design

Canonical: https://deep-learning-study-room.vercel.app/read/cn/m2/formulas/formulas--design/

M2 · symbols explained; worked examples linked below



$$
2^h-2\geq H
$$



H requested usable hosts. Smallest sufficient h gives smallest ordinary subnet.



$$
2^s\geq K,\quad p_{new}=p_{old}+s
$$



K equal subnets required; s borrowed bits. Do not subtract two from modern subnet count.



$$
p=32-\log_2(N)
$$



For a power-of-two total address requirement, subject to boundary alignment.

## Learn it with complete solutions

[Three full VLSM designs](https://deep-learning-study-room.vercel.app/read/cn/m2/read/cidr--vlsm-1/)