Reputation · trust score
A transparent 0–100 signal. Every entity starts at a neutral baseline of 65; threat-intel blocklists, exposure, reverse-DNS, routing and allocation each adjust it up or down. Higher is more trustworthy.
- Baseline (neutral) 65
- Trust score 65 / 100
Experimental · trust-vectors model v1.2.0 — a transparent heuristic, not a definitive verdict. How it works →
Top CIDR ranges
| CIDR | IPs | PTR Density | Organization | Country | State | City |
|---|---|---|---|---|---|---|
| 217.21.168.0/21 | 2.0K |
98.4%
|
C.T.CO. Ltd. | LV | — | — |
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS15721 actually originates in BGP, observed across our RIPE RIS collectors. This live routing view can differ from the registry allocation above.
| Prefix | Announcement samples | Last seen |
|---|---|---|
| 217.21.168.0/21 | 10,664 | 2026-08-02 22:11:50 |
| 217.21.168.0/22 | 5,876 | 2026-08-02 22:11:46 |
| 217.21.172.0/22 | 5,824 | 2026-08-02 22:11:46 |
Frequently Asked Questions
What is AS15721?
AS15721 is an Autonomous System Number assigned to C.T.CO. Ltd.. An ASN identifies a network that controls a specific set of IP addresses and determines how traffic is routed across the internet via BGP (Border Gateway Protocol).
How many IP addresses does AS15721 announce?
AS15721 announces 2.0K IPv4 addresses distributed across 1 routed CIDR prefixes. The network is registered in Latvia.
Who operates AS15721?
AS15721 is operated by C.T.CO. Ltd.. The organization is based in Latvia. You can view all IP ranges and related ASNs on the organization page.
What country is AS15721 registered in?
AS15721 is registered in Latvia. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
