Azure westus IP ranges

Microsoft Azure region

The Microsoft Azure region westus uses 1,362 IPv4 and 229 IPv6 blocks, covering about 2.1 million unique IPv4 addresses. It is one of 78 Azure regions with published address ranges.

IPv4 blocks
1,362
IPv6 blocks
229
Unique IPv4 addresses
2,125,808

Range data updated 2026-11-07

westus address prefixes

The first 1,000 of 1,591 prefixes are listed.

Using these ranges

Region prefix lists are used to allowlist traffic from workloads in westus, to route or geofence by cloud region, and to recognise Azure infrastructure in logs. Prefixes move between regions and services over time, so refresh any allowlist regularly rather than hard-coding it. An address inside these ranges tells you which network hosts it, not who is renting it; check each address's profile for risk evidence.

Azure ranges are shared between customer workloads and Microsoft-operated services. An address in a regional compute range is usually a customer virtual machine; Microsoft's own crawlers and mail systems have separate, verifiable identities.

Other Azure regions

All Microsoft Azure IP ranges · All providers · IP address lookup