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 v1.1.0 — a transparent heuristic, not a definitive verdict. How it works →
Top CIDR ranges
| CIDR | IPs | PTR Density | Organization | Country | State | City |
|---|---|---|---|---|---|---|
| 204.75.18.0/23 | 512 |
12.3%
|
Fastmail Pty Ltd | AU | — | — |
| 103.168.172.0/24 | 256 |
54.3%
|
Fastmail Pty Ltd | AU | — | — |
| 202.12.124.0/24 | 256 |
37.1%
|
Fastmail Pty Ltd | AU | — | — |
| 204.75.18.0/24 | 256 |
0.0%
|
— | NL | North Holland | Amsterdam |
| 204.75.19.0/24 | 256 |
0.0%
|
— | US | Missouri | St Louis |
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS151847 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 |
|---|---|---|
| 204.75.19.0/24 | 24,858 | 2026-07-21 02:38:20 |
| 204.75.18.0/24 | 19,326 | 2026-07-21 03:05:50 |
| 202.12.124.0/24 | 13,354 | 2026-07-21 02:38:19 |
| 103.168.172.0/24 | 5,932 | 2026-07-21 03:14:56 |
| 204.75.18.0/23 | 5,412 | 2026-06-06 20:17:05 |
Frequently Asked Questions
What is AS151847?
AS151847 is an Autonomous System Number assigned to Fastmail Pty 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 AS151847 announce?
AS151847 announces 1.0K IPv4 addresses distributed across 3 routed CIDR prefixes. The network is registered in United States.
Who operates AS151847?
AS151847 is operated by Fastmail Pty Ltd. The organization is based in United States. You can view all IP ranges and related ASNs on the organization page.
What country is AS151847 registered in?
AS151847 is registered in United States. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
