T-Mobile US IP Ranges
T-Mobile US runs the mobile network its subscribers connect from, registered with ARIN as AS21928 to T-Mobile USA, Inc. in June 2002. Two of its largest blocks begin one address after a reserved range, which is why they are so often mistaken for private space.
- Provider
- T-Mobile US
- Primary ASN
- AS21928
- Category
- ISP
- Headquarters
- Bellevue, WA, USA
- Announced IPv4 prefixes
- 269
- Registry
- ARIN
Known IP ranges
These prefixes are currently announced to the global routing table by AS21928 (T-MOBILE-AS21928 - T-Mobile USA, Inc.). Prefix sets change over time - use WHOIS Lookup for the authoritative record on any specific address.
100.128.0.0/9
162.160.0.0/11
172.32.0.0/11
162.184.0.0/15
172.58.0.0/15
74.60.0.0/16
65.76.0.0/16
172.56.0.0/16
167.20.0.0/16
162.191.0.0/16
2607:fb90::/28
2607:fb90::/32
2607:fb90:6c00::/38 (IPv6)
What does a T-Mobile US IP mean in a privacy test?
A T-Mobile address as your visible IP means the request reached the site over the mobile network with nothing tunnelling it. It is a weaker statement about location than a fixed line would be: the handset network is IPv6-only, and the IPv4 address a site records is the one T-Mobile's translator used on the way out, shared with other subscribers on the same gateway rather than assigned to a phone.
Where to get T-Mobile's address list
There is no T-Mobile equivalent of a cloud provider's ranges file. Consumer carriers do not publish firewall allowlists, because an allowlist exists so other people can admit your servers and a carrier's addresses belong to its customers instead. The registry is the source that can be checked: ARIN holds AS21928 under the AS name T-MOBILE-AS21928, registered to T-Mobile USA, Inc. on 12 June 2002, and the prefixes announced under it are the blocks listed above. The AS21928 page on this site carries the same registry record with the routing detail beside it.
Two of those prefixes deserve a second look before anyone writes a rule against them. 100.128.0.0/9 starts immediately after 100.64.0.0/10, the shared address space RFC 6598 set aside for carrier NAT, and 172.32.0.0/11 starts immediately after 172.16.0.0/12, the private range from RFC 1918. Both T-Mobile blocks are ordinary public space, and both get typed into filters as though they were reserved. A rule that treats them as private silently drops real subscribers.
What a T-Mobile address says about the device behind it
AS21928 carries subscriber connections rather than rented machines, so this is the opposite case to a hosting range: there is no arbitrary third-party software to account for, and an address here belongs to a phone, a tablet or a home gateway rather than to a server anybody could sign up for. What it is not is a stable identifier. T-Mobile's handset network runs IPv6-only with 464XLAT, the translation architecture published as RFC 6877 and co-authored from inside T-Mobile USA, so the IPv4 address a website logs was produced by a translator in the operator's core rather than configured on the device.
Two things follow for anyone reading logs. The same public address stands in for many subscribers at once and moves as sessions move between gateways, so seeing one twice is weak evidence that it was the same person. And an inbound connection to one is unusual by construction, because there is no port on the far side of a translator for it to reach. Geolocation follows the translator too, which is why a T-Mobile lookup tends to land on a metro rather than a neighbourhood.
Related tools
Frequently asked questions
What IP ranges does T-Mobile US use?
T-Mobile US announces its addresses under AS21928, registered with ARIN to T-Mobile USA, Inc. The largest blocks currently in the routing table are listed above, among them 100.128.0.0/9, 162.160.0.0/11 and 172.32.0.0/11. T-Mobile publishes no machine-readable list of them, so the ARIN record for AS21928 is the source that can be checked.
Why does a T-Mobile US IP appear in my privacy test?
A T-Mobile address as your visible IP means the request reached the site over the mobile network with nothing tunnelling it. It is a weaker statement about location than a fixed line would be: the handset network is IPv6-only, and the IPv4 address a site records is the one T-Mobile's translator used on the way out, shared with other subscribers on the same gateway rather than assigned to a phone.
Is 172.32.x.x or 100.128.x.x a private IP address?
No, and the confusion is easy to see. RFC 1918 reserves 172.16.0.0/12, which ends at 172.31.255.255, and RFC 6598 reserves 100.64.0.0/10, which ends at 100.127.255.255. T-Mobile announces 172.32.0.0/11 and 100.128.0.0/9, which begin one address later. Both are routable public space.
Why does my T-Mobile IP address keep changing?
Because it was never assigned to your device. The handset network is IPv6-only and reaches IPv4 sites through a translator, so the public IPv4 address a site records belongs to that translator's pool and is shared with other subscribers. It changes as sessions move between gateways rather than on a schedule you control.
Does T-Mobile publish a list of its IP ranges?
No. A carrier publishes an allowlist only when other networks need to admit its servers, and nothing about a consumer mobile network calls for that. The addresses announced under AS21928 are visible in the ARIN registry record and in the global routing table, which is where the blocks above come from.