# Azure networking cheat sheets and reference

> Reference cheat sheets for Azure networking: VNet and subnet sizing, five reserved IPs per subnet, verified Azure CLI commands, and official service limits.

- Page URL: https://itinsighthub.com/azure/
- Markdown variant of this page: append `?format=md` to any URL on this site or send `Accept: text/markdown`.
- Full site index for AI assistants: https://itinsighthub.com/llms.txt
- Full site export: https://itinsighthub.com/llms-full.txt

# Azure cheat sheets

These cheat sheets cover the parts of Azure networking that trip people up most: how to size VNets and subnets, how the documented address reservation changes usable counts, and the exact syntax for the CLI commands that create all of it. Every figure below comes from Microsoft Learn documentation.[Networking limits](https://itinsighthub.com/azure/limits/) has the hard caps; [VNet and subnet sizing](https://itinsighthub.com/azure/networking/) has the arithmetic; [Azure CLI reference](https://itinsighthub.com/azure/cli/) has copy-ready commands.

Use the calculators alongside the sheets when you design: [IPv4 subnet calculator](https://itinsighthub.com/subnet-calculator/) for per-prefix breakdowns, [IP range to CIDR](https://itinsighthub.com/ip-range-to-cidr/) to turn a planned range into clean CIDR blocks, and [VLSM calculator](https://itinsighthub.com/vlsm-calculator/) to right-size a whole plan from host requirements instead of guessing.

## Cheat sheets

### Networking

VNet address spaces, the five reserved IPs per subnet, and a usable-address table from /16 to /29.

### Azure CLI

Verified az login, group, VNet, subnet and VM commands with the documented flag names.

### Limits

Official caps for VNets, subnets, NSGs, peerings and public IPs under Resource Manager.

## Network tools

[Subnet Calculator](https://itinsighthub.com/subnet-calculator/)[IPv6 Calculator](https://itinsighthub.com/ipv6-subnet-calculator/)[Wildcard Mask](https://itinsighthub.com/wildcard-mask-calculator/)[Range → CIDR](https://itinsighthub.com/ip-range-to-cidr/)[Splitter](https://itinsighthub.com/subnet-splitter/)[Aggregator](https://itinsighthub.com/cidr-aggregator/)[VLSM Calculator](https://itinsighthub.com/vlsm-calculator/)[Practice](https://itinsighthub.com/subnetting-practice/)[Cheat Sheet](https://itinsighthub.com/subnet-cheat-sheet/)

## FAQ

**What is the smallest subnet Azure allows?**

/29. Azure does not support smaller subnets — /31 and /32 point-to-point style ranges are not available — and the five-address platform reservation leaves just 3 usable IPs in that /29.

**How many usable IPs does a /24 subnet have in Azure?**

251. Azure reserves the first four addresses (network, default gateway and two Azure DNS mappings) plus the last address of the range, so usable = 256 − 5 = 251.

**How do peering limits affect deep VNet designs?**

Peer with purpose: 500 peerings per VNet, 128,000 total private addresses across the whole peered group, no transitive peering, and overlapping address spaces cannot be peered. Peering bandwidth is not limited — throughput is bound only by the connecting VMs or NICs.

**Where can I check the math instead of memorizing it?**

Use the subnet calculator for per-prefix usable counts, the VLSM calculator when designing multiple subnets from host requirements, and the IP range to CIDR tool when a range needs converting to clean CIDR blocks.

---

© 2026 ITInsightHub · [About](https://itinsighthub.com/about/) · [Contact](https://itinsighthub.com/contact/) · [Privacy](https://itinsighthub.com/privacy/)