AS12257 — EMC-AS12257

AS12257 announces 36 IPv4 prefixes covering 16,128 addresses and 4 IPv6 prefixes.

About this network

A Dell corporate network, inherited from EMC and still registered under the EMC name.

What it's used for

• Internal enterprise networking for the storage and infrastructure side of Dell, the part of the company that was EMC before the 2016 acquisition.

Notable

• The AS handle is EMC-AS12257 and the netnames read EMC-B2 and EMC-B5, but every registrant is Dell, Inc. Dell bought EMC in what was then the largest technology acquisition ever made, and a decade later the network still carries the acquired company's naming with the buyer's name on the paperwork.
• 36 IPv4 prefixes for only 16,000 addresses, against 14 observed BGP neighbours. Finely subdivided space with a moderate number of adjacencies — a large distributed corporate network rather than a service provider.
• Most of it comes out of 128.221.0.0/16, a legacy class B that EMC held from early on.

Interesting

• One block breaks the naming pattern entirely with the netname DGPDN3, unrelated to the EMC-B series around it. Corporate networks accumulate these: a block requested by one team, under one convention, that nobody ever went back to align with the rest.

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

Announced prefixes

• 12.7.200.0/24
• 128.221.208.0/23
• 128.221.212.0/22
• 128.221.216.0/21
• 128.221.224.0/22
• 128.221.228.0/24
• 128.221.230.0/23
• 128.221.232.0/23
• 128.221.235.0/24
• 128.221.237.0/24
• 128.221.239.0/24
• 132.237.141.0/24
• 137.69.113.0/24
• 137.69.117.0/24
• 147.178.2.0/24
• 147.178.4.0/22
• 147.178.8.0/24
• 152.62.97.0/24
• 152.62.108.0/23
• 152.62.110.0/24
• 152.62.112.0/23
• 152.62.115.0/24
• 152.62.118.0/24
• 152.62.154.0/23
• 152.62.163.0/24
• 152.62.164.0/23
• 152.62.184.0/22
• 152.62.193.0/24
• 163.244.40.0/24
• 163.244.72.0/24
• 168.159.160.0/24
• 168.159.162.0/24
• 168.159.212.0/23
• 168.159.215.0/24
• 198.161.247.0/24
• 199.245.235.0/24
• 2607:f2b1:70::/47
• 2620:145:400::/48
• 2620:145:800::/38
• 2a01:6f40:f100::/48

Upstream networks

• AS3356 Level 3 Parent, LLC
• AS8220 COLT Technology Services Group Limited
• AS1273 IDDQD-AS
• AS12400 Partner Communications Ltd.
• AS7018 AT&T Enterprises, LLC
• AS701 Verizon Business
• AS9498 BHARTI Airtel Ltd.
• AS12849 Hot-Net internet services Ltd.
• AS4657 StarHub Ltd
• AS198949 Radware Ltd
• AS4755 TATA Communications formerly VSNL is Leading ISP
• AS5400 British Telecommunications Limited
• AS2686 AT&T Enterprises, LLC

Adjacent networks

• AS3356 Level 3 Parent, LLC
• AS8220 COLT Technology Services Group Limited
• AS1273 IDDQD-AS
• AS12400 Partner Communications Ltd.
• AS7018 AT&T Enterprises, LLC
• AS701 Verizon Business
• AS9498 BHARTI Airtel Ltd.
• AS12849 Hot-Net internet services Ltd.
• AS198949 Radware Ltd
• AS4657 StarHub Ltd
• AS4755 TATA Communications formerly VSNL is Leading ISP
• AS5400 British Telecommunications Limited
• AS2686 AT&T Enterprises, LLC