AS11951 — MCSP
AS11951 announces 5 IPv4 prefixes covering 37,376 addresses and 0 IPv6 prefixes.
About this network
MCSP is Medical Computer Systems, trading as MCSP, Inc — a Washington, DC provider that describes itself as an internet, application and managed-services company: fibre and Ethernet access, colocation, hosted mail and voice, backup and cloud applications for small and mid-sized businesses.
What it's used for
A mixed provider estate rather than a single-purpose network. RIS sees 11 prefixes carrying 37,376 addresses behind only two observed neighbours — a lot of address space reached through very few upstreams, which rules out any wholesale role. The reverse DNS shows both halves of the business at once: first-party infrastructure (core1-...wadc.mcsp.net, mcsppnt.mcsp.net, edge1.meva.mcsp.net), shared hosting serving customer sites and mail, and access pools under dsl.lan2wan.com and dialisp.net.
Notable
The prefix registrants look alarming until you read them properly. The blocks belong to MAI Network Services, Sytex Access, Lan2Wan, Management Analysis Inc and MCSP itself — five names, one AS. This is not the IP-leasing shape: everything is in a single registry, the rDNS is first-party throughout, and the holder is a findable business at a real DC address. It reads as a roll-up of small legacy ISPs whose registry records were never renamed, with their subscriber pools still answering under the acquired brands.
Interesting
Blocks here still carry dial-up (dialisp.net) and DSL naming, a working fossil layer beneath the colocation and cloud services the company sells today.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.
Announced prefixes
- 66.186.128.0/20
- 204.152.42.0/23
- 205.147.160.0/19
- 207.152.128.0/18
- 209.50.192.0/19
Upstream networks
Adjacent networks
awaiting query
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