2.1.1. Planning VNet Address Spaces

Azure VNets use RFC 1918 private address ranges. Your job is to allocate these ranges without overlap and with room for growth.

Available Private Ranges:

Planning Considerations:

1. Document existing on-premises networks – VNet ranges must not overlap with anything you'll connect to
2. Reserve space per region – Assign non-overlapping ranges to each Azure region
3. Size for growth – A /16 per VNet provides 65,536 addresses and easy mental math
4. Leave gaps – Don't use contiguous ranges for all VNets; leave room to insert new networks

Example Enterprise Allocation:

⚠️ Exam Trap: Azure reserves 5 IP addresses in each subnet (first 4 and last). A /24 subnet provides 251 usable addresses, not 256.