AS11647 — SENTEX-NET

AS11647 announces 21 IPv4 prefixes covering 23,296 addresses and 2 IPv6 prefixes.

About this network

SENTEX-NET is Sentex Communications, a long-established independent internet provider based in Cambridge, Ontario, serving southwestern Ontario. RIS sees 32 IPv4 prefixes and about 23,300 addresses, 2 IPv6 prefixes (2607:f3e0::/32 and a /48), and 14 observed BGP neighbours.

What it's used for

Regional access and business connectivity. The reverse DNS is the clearest evidence of what the space carries: names like p4j.xDSL-1mm.sentex.ca, dimplex-dsl.sentex.ca and 67-43-136-5.agas1a-dynamic.dsl.sentex.ca are subscriber access, with an explicitly dynamic DSL pool among them, while dw3-lo0.sentex.ca, dw4blo0.sentex.ca and ipsec-test.sentex.ca are the operator's own routers and service hosts. This is an eyeball network with a substantial business-access side, not a pure enterprise and not a wholesale carrier — 14 neighbours is a mid-sized ISP with several upstreams and peering, an order of magnitude short of a transit provider.

The prefix registrants deserve a careful read rather than an alarm. Most blocks register to Sentex itself (SENTEXCO, SENTEXCO2), but three register to other companies: Com Dev Ltd., Toy Com, and Junior Mine Services Ltd. These are not a leased-address tell. They are ordinary SWIP reassignments to named business customers — the pattern of an ISP that has been assigning space to local firms for decades — and the reverse DNS confirms it: 199.71.252.5 answers as eldon.toy.com, a customer running its own naming, while addresses inside the Junior Mine block still answer under sentex.ca.

Notable

Com Dev was a Cambridge, Ontario space-hardware manufacturer, which is about as local a customer as a Cambridge ISP could have. Customer names preserved in the registry are a kind of fossil record of a regional provider's history.

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

Announced prefixes

• 64.7.128.0/19
• 67.43.128.0/20
• 98.159.240.0/20
• 192.139.233.0/24
• 198.73.181.0/24
• 198.73.240.0/24
• 198.235.180.0/22
• 199.71.182.0/23
• 199.71.252.0/24
• 199.85.118.0/23
• 199.212.134.0/23
• 199.246.36.0/23
• 204.138.108.0/24
• 204.187.87.0/24
• 205.210.141.0/24
• 205.211.164.0/23
• 206.51.23.0/24
• 206.51.24.0/23
• 206.130.75.0/24
• 206.130.87.0/24
• 206.130.91.0/24
• 2607:f3e0::/32
• 2620:13::/48

Upstream networks

• AS174 Cogent Communications, LLC
• AS3257 GTT Communications Inc.
• AS6939 Hurricane Electric LLC
• AS22652 Videotron Ltee
• AS24482 SG.GS
• AS394256 Tech Futures Interactive Inc.
• AS1403 EBOX
• AS35280 F5 Networks SARL
• AS20473 The Constant Company, LLC

Adjacent networks

• AS174 Cogent Communications, LLC
• AS3257 GTT Communications Inc.
• AS6939 Hurricane Electric LLC
• AS22652 Videotron Ltee
• AS24482 SG.GS
• AS394256 Tech Futures Interactive Inc.
• AS1403 EBOX
• AS35280 F5 Networks SARL
• AS20473 The Constant Company, LLC

Internet exchanges

• Toronto Internet Exchange — Toronto, Canada