Autonomous system
AS13548 CHARLESTON-AS
Unclassified ARIN
Summary
College of Charleston
education research infrastructure
Twelve prefixes that tile a /16 exactly, without the /16 itself ever being announced.
What it's used for
- A university's network. 65,536 addresses across twelve IPv4 prefixes, three observed BGP neighbours, and no IPv6 announced.
Notable
- The prefixes run
153.9.0.0/17, two /19s, two /20s, three /21s, a /22, a /23 and two /24s. - Laid end to end they cover the whole of
153.9, and the covering block is not announced. - All twelve carry the same netname,
CHARLESTON-NET, registered to the college. - Eighteen addresses were queried for reverse DNS and none returned a name.
Interesting
- Announcing every piece of a block but never the block itself is a choice with consequences. It costs eleven extra entries in every routing table on the internet and buys nothing unless the pieces are going different ways, and with one netname and three neighbours they are not obviously doing that.
- The halving pattern, each prefix half the size of the one before, is what a configuration generator produces when told to split a range and never told to stop. Nobody sat down and chose a /23 at
153.9.252. - The registry sees one object, the routing table sees twelve. The mismatch is the useful part: the campus was numbered once, decades ago, and the fragmentation happened later and separately.
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 2026-10-26, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 12 prefixes · 65.54K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 12 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS13548- Registry name
- CHARLESTON-AS
- Registrant
- College of Charleston
- Abuse contact
- abuse@cofc.edu
- Registered
- 2007-06-06
- Last changed
- 2012-03-02
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 3 with no ROA
- ROAs
- 0 authorising AS13548
- ASPA
- no ASPA record
- IRR
- 100% registered · 3 of 3 announcements
- Route objects
- 1 naming AS13548
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: 443 networks and 1,779 prefixes, as published 2026-10-24. 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