Autonomous system
AS15518 CIRC-AS Schulze-Delitzsch-Str.36
Unclassified RIPE NSP
Summary
Circular Informationssysteme
isp hosting business
Four naming schemes in one reverse zone, and one address answers on a customer's domain.
What it's used for
- An internet services company. Six IPv4 prefixes and one IPv6
/32announced from Germany, nearly eight thousand addresses, through two observed BGP neighbours.
Notable
- Some names put the last octet first and the third octet second, joined by a dash.
- Others give the whole address in forward order with dots, inside a single label.
- One is not an address at all: a word for link, a subscriber line product code, and what reads as a site or customer name.
- One answers on an entirely different company's domain, and the rest sit under the operator's own.
- Netnames use two date formats, one with a two-digit year and one with four, so the two allocations were recorded under different conventions.
- Eighteen addresses were queried for reverse DNS and fourteen returned a name.
Interesting
- Four schemes in one zone is the record of four moments when somebody needed a name and wrote one. None of them is wrong; together they mean no tool can parse this zone reliably.
- The registrant roles are worth keeping: alongside the company, two role objects named for a network master and a guardian, which is more character than these fields usually carry.
- The AS handle continues into a street name and number with no space before the digits, postal information pushed into a network identifier.
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 2026-10-15, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 6 prefixes · 7.94K addresses IPv6 1 prefixes
| Country | Name | Prefixes |
|---|---|---|
| DE | Germany | 7 |
Registry
Allocation record
- Registry
- RIPE
- Handle
AS15518- Registry name
- CIRC-AS
- Registrant
- CIRCULAR-NET
- Abuse contact
- guardian@circular.net
- Registered
- 2002-08-22
- Last changed
- 2025-10-24
- Allocation
- allocated
Declared
PeeringDB profile
- Name
- circular Informationssysteme
- Network type
- NSP
- Scope
- Europe
- Traffic ratio
- Mostly Inbound
- Peering policy
- Open
- Website
- http://www.circular.de
PeeringDB records are maintained by the network operator and are not independently verified. Treat them as a statement of intent rather than of fact. For the observed and recorded view, see peering, which lists the exchanges Packet Clearing House has a port on file for.
Routing security
RPKI and IRR
- RPKI
- 100% valid · 6 valid, 0 with no ROA
- ROAs
- 10 authorising AS15518
- ASPA
- no ASPA record
- IRR
- 100% registered · 6 of 6 announcements
- Route objects
- 12 naming AS15518
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 1,782 prefixes, as published 2026-10-16. 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