asn.dev

Autonomous system

AS27336 SENTARA-HEALTH-CARE

Unclassified ARIN

IPv4 addresses 65.54K 31 prefixes
IPv6 prefixes 0 counted as prefixes, not addresses
Countries 1 mostly US
Exchanges 0 recorded by PCH
Upstreams 4 0 downstream
Flagged prefixes 0 none

Summary

Sentara Healthcare

United States of America · AI-generated

healthcare business corporate internal

The AS handle SENTARA-HEALTH-CARE is held by Sentara Healthcare.

What it's used for

  • The address space carries internal corporate infrastructure for a not-for-profit integrated healthcare system, with all registrants and netnames identified as SENTARA and Sentara Healthcare.
  • The AS announces 65536 IPv4 addresses across 31 prefixes while maintaining only 4 observed neighbours, a ratio that indicates an internal corporate estate with site-by-site segmentation rather than an access or transit network.

Notable

  • All RDAP registrants for the largest prefixes agree with the announcer, consistently listing Sentara Healthcare as the registrant and SENTARA as the netname.
  • The address inventory is entirely IPv4, with no IPv6 prefixes in the inventory, and is finely subdivided into multiple /20, /21, /22, and /23 blocks within the 163.230.0.0/16 range.

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

4 upstream, 0 downstream and 4 adjacent networks observed; most-used upstreams first.

ASNetworkPaths seen
AS22773Cox Communications Inc.780
AS7795LUMOS Networks, Inc.384
AS33657Comcast Cable Communications, LLC74
AS3356Level 3 Parent, LLC60

Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-16, 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 31 prefixes · 65.54K addresses IPv6 0 prefixes

CountryNamePrefixes
USUnited States of America31

Registry

Allocation record

ARIN · via Atlas (registry + RDAP)
Registry
ARIN
Handle
AS27336
Registry name
SENTARA-HEALTH-CARE
Registrant
Sentara Healthcare
Abuse contact
wan@sentara.com
Registered
2003-02-14
Last changed
2012-03-02
Allocation
assigned

Routing security

RPKI and IRR

Full detail
RPKI
0% valid · 0 valid, 22 with no ROA
ROAs
0 authorising AS27336
ASPA
no ASPA record
IRR
100% registered · 22 of 22 announcements
Route objects
22 naming AS27336

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 2026-10-17. 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