Autonomous system
AS21928 T-MOBILE-AS21928
Mobile ARIN
Summary
T-Mobile US
isp mobile eyeball
T-Mobile US (T-MOBILE-AS21928) — one of the three big US mobile carriers, and increasingly a home-internet provider via 5G fixed wireless.
What it's used for
- Mobile data for tens of millions of subscribers, plus T-Mobile Home Internet (5G fixed wireless).
Notable
- A large "eyeball" network — addresses here are typically mobile devices or fixed-wireless homes, often behind carrier-grade NAT.
- Grew by merging with Sprint in 2020.
Interesting
- T-Mobile's "Un-carrier" strategy and the Sprint merger reshaped US mobile competition into a three-carrier market.
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
Recorded at 14 exchanges in 2 countries, largest first.
| Exchange | Location | Their address |
|---|---|---|
| Equinix Internet Exchange Ashburn | Ashburn, United States | 206.126.237.181 |
| Seattle Internet Exchange | Seattle, United States | 206.81.81.35 |
| Coresite - Any2 West | Los Angeles, United States | 206.72.211.22 |
| Any2 California | Los Angeles, United States | 206.72.211.22 |
| Equinix Internet Exchange Chicago | Chicago, United States | 208.115.136.217 |
| Equinix Internet Exchange Dallas | Dallas, United States | 206.223.118.210 |
| New York International Internet Exchange | New York, United States | 198.32.160.245 |
| FL-IX - The Florida Internet Exchange / Community IX - Florida | Miami, United States | 206.41.108.20 |
Transit providers
19 upstream, 3 downstream and 32 adjacent networks observed; most-used upstreams first.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-11, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 133 prefixes · 13.12M addresses IPv6 194 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 327 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS21928- Registry name
- T-MOBILE-AS21928
- Registrant
- T-Mobile USA, Inc.
- Abuse contact
- abuse@t-mobile.com
- Registered
- 2002-06-12
- Last changed
- 2012-02-24
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 100% valid · 544 valid, 0 with no ROA
- ROAs
- 74 authorising AS21928
- ASPA
- no ASPA record
- IRR
- 99.4% registered · 541 of 544 announcements
- Route objects
- 1,399 naming AS21928
Reputation
Classification and threat
Mobile Cellular carrier. Addresses are shared by many handsets via CGNAT.
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: 431 networks and 1,768 prefixes, as published 2026-10-12. 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