Autonomous system
AS3598 MICROSOFT-CORP-AS
Unclassified ARIN
Summary
Microsoft Corporation
enterprise legacy
MICROSOFT-CORP-AS is one of Microsoft's long-held AS numbers, registered to
One Microsoft Way in Redmond, Washington. It carries Microsoft's corporate-side
networks rather than the Azure cloud.
What it's used for
- Microsoft's own corporate and internal networks — the classic
131.107.0.0/16and167.220.0.0/16ranges long associated with Microsoft's corporate and research environments. - Company infrastructure and services that sit outside the public cloud's address space.
Notable
- Corporate, not cloud. Microsoft's public cloud and CDN traffic mostly rides other ASNs; addresses seen under AS3598 are typically Microsoft's own employees, offices, labs, and internal systems.
- Because it is corporate space, an IP here usually means "Microsoft the company" rather than "a customer renting a Microsoft VM" — a useful distinction when attributing traffic.
Interesting
- The low AS number dates from Microsoft's arrival on the routed internet in the early 1990s, well before the company had a cloud business at all.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Address space
Summary
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 108 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS3598- Registry name
- MICROSOFT-CORP-AS
- Registrant
- Microsoft Corporation
- Abuse contact
- abuse@microsoft.com
- Registered
- 1994-05-18
- Last changed
- 2013-08-21
- Status
- active
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
No IC3 indicators Nothing from the FBI IC3 feed.
Threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere