asn.dev

Autonomous system

AS11951 MCSP

Unclassified ARIN

IPv4 addresses 37.38K 12 prefixes
IPv6 prefixes 0 counted as prefixes, not addresses
Countries 1 mostly US
Exchanges 0 recorded by PCH
Upstreams 2 0 downstream
Flagged prefixes 0 none

Summary

MCSP, Inc (Medical Computer Systems)

United States · AI-generated

hosting isp enterprise legacy

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. Source, and how to suggest an edit.

Interconnection

Peering at a glance

Full topology · Graph

Internet exchanges

No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.

Transit providers

2 upstream, 0 downstream and 2 adjacent networks observed; most-used upstreams first.

ASNetworkPaths seen
AS174Cogent Communications, LLC424
AS33657Comcast Cable Communications, LLC159

Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-19, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.

Address space

Summary

Shape and geography

IPv4 12 prefixes · 37.38K addresses IPv6 0 prefixes

CountryNamePrefixes
USUnited States of America12

Registry

Allocation record

ARIN · via Atlas (registry + RDAP)
Registry
ARIN
Handle
AS11951
Registry name
MCSP
Registrant
Medical Computer Systems
Abuse contact
pdw@mcsp.com
Registered
1999-02-12
Last changed
2021-07-14
Allocation
assigned

Routing security

RPKI and IRR

Full detail
RPKI
0% valid · 0 valid, 10 with no ROA
ROAs
0 authorising AS11951
ASPA
no ASPA record
IRR
100% registered · 10 of 10 announcements
Route objects
12 naming AS11951

Reputation

Classification and threat

Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.

Spamhaus DROP

Not on ASN-DROP The network as a whole is not listed.

No DROP prefixes None of its announced space is on the DROP prefix list.

Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 442 networks and 1,783 prefixes, as published 2026-10-20. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.

FBI IC3

No IC3 indicators Nothing from the FBI IC3 feed.

IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.

Elsewhere

Cross-check