Autonomous system
AS12076 MICROSOFT
Unclassified ARIN
Summary
Microsoft
enterprise government legacy
An AS registered to Microsoft that announces address space belonging to the United States Patent and Trademark Office.
What it's used for
- Carrying one customer's address space. 2,048 IPv4 addresses in a single
/21, four IPv6/48s, and two observed BGP neighbours.
Notable
- The only IPv4 announcement,
151.207.40.0/21, is registered asPTONETto the United States Patent and Trademark Office, not to Microsoft. - The IPv6 side is four separate announcements —
2608:1c1:1::/48,4::/48,6::/47and8::/48— out of one/32, with the gaps between them left unannounced. - One IPv4 prefix and two neighbours. Whatever this AS is for, it is not general-purpose.
Interesting
- An announcer and a registrant that disagree is one of the more informative shapes in routing data. It usually means one organisation is carrying another's space: a provider announcing a customer's blocks, which is exactly what running a government agency's infrastructure looks like from the outside.
- The netname is
PTONET, from the era when the agency was simply "the PTO". The trademark half of the name arrived in the title long before it arrived in the network registration. - Announcing four
/48s with holes between them, rather than the covering block, keeps the unused space out of the routing table. It also means anyone reading the announcement can count how much of the allocation is actually in service.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-21, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 1 prefixes · 2.05K addresses IPv6 4 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 5 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS12076- Registry name
- MICROSOFT
- Registrant
- Microsoft Corporation
- Abuse contact
- abuse@microsoft.com
- Registered
- 1999-03-16
- Last changed
- 2015-02-23
- Allocation
- assigned
Declared
PeeringDB profile
- Name
- Microsoft Corporation
- Scope
- Not Disclosed
- Traffic ratio
- Not Disclosed
PeeringDB records are maintained by the network operator and are not independently verified. Treat them as a statement of intent rather than of fact. For the observed and recorded view, see peering, which lists the exchanges Packet Clearing House has a port on file for.
Routing security
RPKI and IRR
- RPKI
- 25% valid · 2 valid, 6 with no ROA
- ROAs
- 14 authorising AS12076
- ASPA
- no ASPA record
- IRR
- 25% registered · 2 of 8 announcements
- Route objects
- 11 naming AS12076
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 442 networks and 1,779 prefixes, as published 2026-10-22. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere