Autonomous system
AS11501 VISTAASN - Vista Radiology, P.C.
Unclassified ARIN
Summary
Vista Radiology, P.C.
enterprise legacy
VISTAASN belongs to Vista Radiology, P.C., a physician-owned radiology practice based in Knoxville, Tennessee. It is a single-enterprise network: the practice runs its own AS purely to carry its own clinical traffic, not to sell anything to anyone.
What it's used for
Corporate connectivity for a medical group. Vista Radiology reads imaging for hospitals and imaging centres across East Tennessee, with a main office on Laurel Avenue in Knoxville and partnering sites scattered through the region, so its network exists to move studies between those sites and its radiologists. That is the workload behind the AS: PACS and teleradiology traffic, plus the ordinary back office.
Notable
The routing is about as small and self-contained as a real AS gets. RIS sees 3 IPv4 prefixes and 512 addresses, and the prefix list explains that immediately: a 198.205.6.0/23 plus its two constituent /24s. That is one /23 announced at two granularities, so the practice's entire routed footprint is 512 addresses. No IPv6 is announced at all.
Only 2 observed BGP neighbours. A network that peers with two ASes is buying transit from a small number of providers and selling none, which is exactly what you would expect of a clinical practice that runs BGP for dual-homed redundancy rather than for any network business. All three prefixes are registered to Vista Radiology's own ARIN org, so holder and space agree with no third parties in between.
Interesting
Announcing both the /23 and its halves is a common trick for a dual-homed site: the covering route keeps the block reachable while the more-specifics let each /24 prefer a different upstream. For a practice whose uptime requirement is "the radiologist can open the scan", that redundancy is the whole point of running an AS at this size.
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
Internet exchanges
No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-11-11, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 1 prefixes · 512 addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 1 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS11501- Registry name
- VISTAASN
- Registrant
- Vista Radiology, P.C.
- Abuse contact
- dsliger@vistaradiology.com
- Registered
- 2007-03-06
- Last changed
- 2012-03-02
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 100% valid · 3 valid, 0 with no ROA
- ROAs
- 1 authorising AS11501
- ASPA
- no ASPA record
- IRR
- 100% registered · 3 of 3 announcements
- Route objects
- 3 naming AS11501
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: 453 networks and 1,846 prefixes, as published 2026-11-11. 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