Is it per chance 100.64.0.0/10?
* https://en.wikipedia.org/wiki/IPv4_shared_address_space
It could be 21.0/8
ref:https://old.reddit.com/r/tmobileisp/comments/1gg7361/why_is_...
I booted an LTE router using a T-Mobile SIM.
Within an hour I had changed WAN IP. Both were from AS749 US-DOD NIC
in 33.79.135.0/24 & 21.140.100.0/24.
alt Hacker News
It could be 21.0/8
ref:https://old.reddit.com/r/tmobileisp/comments/1gg7361/why_is_...
I booted an LTE router using a T-Mobile SIM.
Within an hour I had changed WAN IP. Both were from AS749 US-DOD NIC
They were cgnat'd behind TMble's advertised asn.