Autonomous system
AS13965 SBCIS-FYTVAR
Unclassified ARIN
Summary
AT&T Enterprises
mobile telecom transit
Two of the four IPv6 prefixes sit next to each other and are announced separately anyway.
What it's used for
- A mobile carrier's network. 4,096 addresses across seven IPv4 prefixes, four IPv6 prefixes, and three observed BGP neighbours.
Notable
- Every IPv4 block is netname
ATT-MOBILITY-LLC, registered toAT&T Enterprises, LLC. - The IPv6 prefixes are
2600:381:3900::/40,2600:387:14::/48,2606:ae00:6300::/42and2606:ae00:6380::/42. - The last two are adjacent halves of a single larger range.
- The AS handle is
SBCIS-FYTVAR, a carrier code followed by six letters. - Eighteen addresses were queried for reverse DNS and none returned a name.
Interesting
- Announcing two adjacent halves rather than the whole is a choice that costs an extra routing entry and buys the ability to steer each half differently. In a mobile network that usually means different regions or different equipment behind each one.
- The six letters on the handle are not an abbreviation of anything in the record. Large carriers name AS numbers from internal inventories, so the string identifies the network precisely inside one company and means nothing outside it.
- The netname names one subsidiary and the registrant another, both belonging to the same parent. The registry follows whichever entity signed, and reorganisations move that entity more often than they move the addresses.
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 2026-10-26, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 7 prefixes · 4.10K addresses IPv6 2 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 9 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS13965- Registry name
- SBCIS-FYTVAR
- Registrant
- AT&T Enterprises, LLC
- Abuse contact
- abuse@att.net
- Registered
- 1999-09-28
- Last changed
- 2024-12-05
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 82% valid · 9 valid, 2 with no ROA
- ROAs
- 7 authorising AS13965
- ASPA
- no ASPA record
- IRR
- 100% registered · 11 of 11 announcements
- Route objects
- 12 naming AS13965
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: 446 networks and 1,852 prefixes, as published 2026-10-27. 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