AS21881
RAPID RESPONSE MONITORING SERVICES INCORPORATED
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 |
|---|---|---|---|---|---|---|
| 216.151.46.0/23 | 512 |
1.0%
|
RAPID RESPONSE MONITORING SERVICES INCORPORATED | US | — | — |
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS21881 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 |
|---|---|---|
| 216.151.47.0/24 | 4,380 | 2026-08-01 22:05:53 |
| 216.151.46.0/24 | 4,289 | 2026-08-01 22:06:01 |
| 216.151.46.0/23 | 4,192 | 2026-08-01 22:05:53 |
| 174.46.231.128/26 | 1 | 2026-06-03 19:43:08 |
Frequently Asked Questions
What is AS21881?
AS21881 is an Autonomous System Number assigned to RAPID RESPONSE MONITORING SERVICES INCORPORATED. 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 AS21881 announce?
AS21881 announces 512 IPv4 addresses distributed across 1 routed CIDR prefixes. The network is registered in United States.
Who operates AS21881?
AS21881 is operated by RAPID RESPONSE MONITORING SERVICES INCORPORATED. The organization is based in United States. You can view all IP ranges and related ASNs on the organization page.
What country is AS21881 registered in?
AS21881 is registered in United States. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
