Autonomous system
AS33733 CASTRO-TELECOM - CASTRO TELECOM LLC
Unclassified APNIC
Summary
Castro Telecom LLC
business telecom leased
The AS handle CASTRO-TELECOM is held by Castro Telecom LLC.
What it's used for
- The address space carries netnames
CASTRO-TELECOMandDUCKYN4, with registrants Castro Telecom LLC and Ducky Networks LLC respectively. - The AS announces 1280 IPv4 addresses across 2 prefixes and has 2 observed neighbours, a ratio that suggests a small-scale access or business network rather than a transit provider.
Notable
- Registrants do not fully agree with the announcer; the /24 prefix is registered to Ducky Networks LLC under the netname
DUCKYN4, while the /22 is registered to Castro Telecom LLC. - The address inventory consists of one /22 and one /24, with no IPv6 prefixes in the inventory.
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 2026-11-01, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 2 prefixes · 1.28K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 2 |
Registry
Allocation record
- Registry
- APNIC
- Handle
AS33733- Registry name
- CASTRO-TELECOM
- Registrant
- CASTRO TELECOM LLC
- Abuse contact
- tomas.leite.castro@tecnico.ulisboa.pt
- Registered
- 2024-01-23
- Last changed
- 2024-01-23
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 50% valid · 1 valid, 1 with no ROA
- ROAs
- 2 authorising AS33733
- ASPA
- no ASPA record
- IRR
- 100% registered · 2 of 2 announcements
- Route objects
- 4 naming AS33733
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: 449 networks and 1,846 prefixes, as published 2026-11-02. 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