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Autonomous System

AS398991

X99

Announced IPs
11,776
CIDR prefixes
20
ASN
AS398991

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.

53/100
Caution
How this score is built

Experimental · trust-vectors model v1.2.1 — a transparent heuristic, not a definitive verdict. How it works →

⚠ 1 MOAS prefix — multiple origin ASNs detected

All MOAS anomalies →

A previously stable prefix originated by AS398991 is now also announced by another ASN (MOAS — Multiple-Origin AS), detected from our RIPE RIS collectors. Often benign (anycast, multi-homing, or a recent transfer) — but it can signal a route leak or prefix hijack, so it's worth inspecting.

PrefixOrigin ASNsLast detected (UTC)
38.247.68.0/23 AS272786, AS398991 2026-10-12 15:28:45

Network profile

Source: PeeringDB →
Network type NSP
Traffic level 1-5Tbps
Geographic scope Global
Traffic ratio Heavy Outbound
Peering policy Open

Present at 4 internet exchanges: FL-IX, Any2West, CIX-NoVA, DE-CIX Dallas: DE-CIX Dallas Peering LAN

Top CIDR ranges

BGP Announced Prefixes

Live BGP anomalies →

Prefixes AS398991 actually originates in BGP, observed across our RIPE RIS collectors. This live routing view can differ from the registry allocation above.

PrefixAnnouncement samplesLast seen
38.99.238.0/23 108,767 2026-10-12 15:02:32
38.183.188.0/23 65,685 2026-10-12 15:11:59
38.183.189.0/24 65,390 2026-10-12 15:11:59
38.183.188.0/24 65,262 2026-10-12 15:11:59
206.109.56.0/24 64,984 2026-10-12 15:16:01
206.109.57.0/24 64,304 2026-10-12 15:16:01
206.109.56.0/23 64,157 2026-10-12 15:16:01
130.250.189.0/24 31,419 2026-10-12 15:12:05
209.131.123.0/24 29,210 2026-10-12 15:16:01
208.122.16.0/24 23,935 2026-10-12 15:02:26
208.122.16.0/23 23,930 2026-10-12 15:02:26
208.122.17.0/24 23,929 2026-10-12 15:02:26
38.46.142.0/24 23,507 2026-10-12 15:11:58
38.100.202.0/23 22,524 2026-10-12 15:02:22
38.100.203.0/24 22,403 2026-10-12 15:02:22
38.99.239.0/24 22,323 2026-10-12 15:02:22
38.99.238.0/24 22,295 2026-10-12 15:02:22
38.46.143.0/24 21,640 2026-10-12 15:15:06
142.99.99.0/24 21,350 2026-10-12 15:15:59
130.250.188.0/23 20,661 2026-10-12 15:28:47
209.131.122.0/23 20,417 2026-10-12 15:15:50
38.46.142.0/23 20,313 2026-10-12 15:02:22
130.250.188.0/24 20,198 2026-10-12 15:28:47
38.247.69.0/24 19,535 2026-10-12 15:02:26
38.247.68.0/24 19,459 2026-10-12 15:02:26
142.99.102.0/23 19,407 2026-10-12 15:16:01
198.13.16.0/23 19,155 2026-10-12 15:02:26
198.13.17.0/24 18,925 2026-10-12 15:02:26
198.13.16.0/24 18,885 2026-10-12 15:02:26
38.247.70.0/23 18,321 2026-10-12 15:28:32
209.131.122.0/24 18,128 2026-10-12 15:12:05
38.247.70.0/24 18,015 2026-10-12 15:28:32
38.247.71.0/24 17,976 2026-10-12 15:28:32
38.100.202.0/24 17,776 2026-10-12 15:28:32
199.245.233.0/24 16,914 2026-10-12 15:11:58
209.131.120.0/23 16,510 2026-10-12 15:15:59
184.154.242.0/23 16,412 2026-10-12 15:11:58
38.135.26.0/23 16,239 2026-10-12 15:11:58
38.247.68.0/23 15,942 2026-10-12 15:02:26
184.154.244.0/23 15,774 2026-10-12 15:28:47
23.231.97.0/24 15,198 2026-10-12 15:15:19
38.81.123.0/24 14,627 2026-10-12 15:11:59
184.154.240.0/23 14,444 2026-10-12 15:11:58
38.81.122.0/23 14,074 2026-10-12 15:11:59
206.109.58.0/23 13,763 2026-10-12 15:02:26
206.109.59.0/24 13,448 2026-10-12 15:02:26
206.109.58.0/24 13,397 2026-10-12 15:02:26
199.245.234.0/24 13,301 2026-10-12 15:15:50
38.135.27.0/24 12,788 2026-10-12 15:28:34
38.135.26.0/24 12,459 2026-10-12 15:28:34

Showing top 50 of 63 announced prefixes by sample volume.

Frequently Asked Questions

What is AS398991?

AS398991 is an Autonomous System Number assigned to X99. 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 AS398991 announce?

AS398991 announces 11.8K IPv4 addresses distributed across 20 routed CIDR prefixes. The network is registered in United States.

Who operates AS398991?

AS398991 is operated by X99. The organization is based in United States. You can view all IP ranges and related ASNs on the organization page.

What country is AS398991 registered in?

AS398991 is registered in United States. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.

Last updated: 2026-10-12 15:39:05 UTC
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