AS13965 — SBCIS-FYTVAR

AS13965 announces 7 IPv4 prefixes covering 4,096 addresses and 2 IPv6 prefixes.

About this network

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 to AT&T Enterprises, LLC.
• The IPv6 prefixes are 2600:381:3900::/40, 2600:387:14::/48, 2606:ae00:6300::/42 and 2606: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.

Announced prefixes

• 107.116.31.0/24
• 107.116.32.0/21
• 107.121.191.0/24
• 107.121.192.0/23
• 107.121.194.0/24
• 107.121.196.0/23
• 107.121.198.0/24
• 2600:381:3900::/40
• 2600:387:14::/48

Upstream networks

• AS7287 AT&T Enterprises, LLC
• AS36149 Hawaiian Telcom Services Company, Inc.
• AS7018 AT&T Enterprises, LLC

Adjacent networks

• AS7287 AT&T Enterprises, LLC
• AS36149 Hawaiian Telcom Services Company, Inc.
• AS7018 AT&T Enterprises, LLC