AS11396 — TWC-ASN

AS11396 announces 8 IPv4 prefixes covering 24,832 addresses and 0 IPv6 prefixes.

About this network

TWC-ASN is not Time Warner Cable. TWC here is The Williams Companies, the Tulsa, Oklahoma natural-gas pipeline and midstream energy operator, and the AS is held by its in-house IT arm, Williams Information Technology LLC. It carries 25 prefixes and roughly 24,800 addresses behind 7 observed neighbours.

What it's used for

Corporate enterprise networking for an energy company. Almost the entire inventory sits inside 151.142.0.0/16, a single contiguous legacy block registered in ARIN as TWC-NET to Williams Information Technology LLC, deaggregated into /19s, /20s and /24s. That pattern (one big block, sliced by site) is what a large multi-site corporate WAN looks like when it advertises regional chunks, not what an ISP or a hosting network looks like.

Reverse DNS settles it: sampled addresses resolve under williams.com, with names like oktulsbcv1.williams.com (Oklahoma / Tulsa, the company's headquarters city) alongside generic ip-151-142-x-y.williams.com host records. Registrant, announcer and rDNS zone all point at the same company.

Notable

Seven neighbours against 24,800 addresses is an enterprise multihoming posture, not a carrier. Williams provides no transit; it buys it, from a small number of upstreams, for a network that serves offices, control centres and pipeline operations across the US Gulf Coast, Appalachia and the Rockies.

Interesting

The handle is a live example of the "famous-looking name" trap: three letters that read as a household cable brand actually stand for a Fortune 500 pipeline company that has held its own /16 for decades.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 151.142.0.0/21
• 151.142.64.0/23
• 151.142.66.0/24
• 151.142.68.0/22
• 151.142.128.0/19
• 151.142.160.0/20
• 151.142.224.0/19
• 170.21.246.0/23

Upstream networks

• AS3356 Level 3 Parent, LLC
• AS7922 Comcast Cable Communications, LLC
• AS33490 Comcast Cable Communications, LLC
• AS33660 Comcast Cable Communications, LLC
• AS35280 F5 Networks SARL
• AS15830 Equinix (EMEA) Acquisition Enterprises B.V.
• AS33287 Comcast Cable Communications, LLC
• AS33659 Comcast Cable Communications, LLC

Adjacent networks

• AS3356 Level 3 Parent, LLC
• AS7922 Comcast Cable Communications, LLC
• AS33490 Comcast Cable Communications, LLC
• AS33660 Comcast Cable Communications, LLC
• AS35280 F5 Networks SARL
• AS15830 Equinix (EMEA) Acquisition Enterprises B.V.
• AS33287 Comcast Cable Communications, LLC
• AS33659 Comcast Cable Communications, LLC