Autonomous system
AS15721 CTCO Riga, Latvia
Unclassified RIPE
Summary
C.T.CO
hosting business isp
Dots inside the company abbreviation, a city and a country inside the AS handle.
What it's used for
- A software company's network. One IPv4
/21announced from Latvia, no IPv6, two thousand and forty-eight addresses, across four observed BGP neighbours.
Notable
- The registered holder name puts a full stop after each letter of the abbreviation and another after the last pair, so four dots appear before the legal form.
- The AS handle drops those dots and adds a city and a country, separated by a comma.
- The single block's netname is the country code, the undotted abbreviation and an allocation date from the same period the number was first seen.
- Three contacts are listed: a hostmaster, the company, and the company's own abuse contact rather than the registry's generic role.
- All three sampled addresses answer, each with the four octets hyphenated in order under the company domain, including the network address of its subnet.
Interesting
- Dots in a company name are harmless in a registry field and awkward everywhere a name gets turned into an identifier. Every other field in this record silently drops them, which is why the netname and the handle disagree with the holder.
- Four upstreams for a single small block is unusual. The address count says a modest office network; the neighbour count says one that is expected to stay reachable when any single path fails.
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 2026-10-14, 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 · 2.05K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| LV | Latvia | 1 |
Registry
Allocation record
- Registry
- RIPE
- Handle
AS15721- Registry name
- CTCO
- Registrant
- CTCO-MNT
- Abuse contact
- sysadmin@ctco.lv
- Registered
- 2001-12-13
- Last changed
- 2023-10-20
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 100% valid · 3 valid, 0 with no ROA
- ROAs
- 1 authorising AS15721
- ASPA
- no ASPA record
- IRR
- 100% registered · 3 of 3 announcements
- Route objects
- 7 naming AS15721
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 1,773 prefixes, as published 2026-10-13. 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