Skip to main content
Autonomous System

AS1101

SURF B.V.

Announced IPs
1,904,128
CIDR prefixes
15
ASN
AS1101

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.

69/100
Moderate
How this score is built
  • Baseline (neutral) 65
  • Enterprise allocation +4
  • Trust score 69 / 100

Experimental · trust-vectors model v1.2.0 — a transparent heuristic, not a definitive verdict. How it works →

About SURFnet

SURF is an organization that develops, implements and maintains the national research and education network (NREN) of the Netherlands. It operates the national research network formally called SURFnet.

Founded
1989
Headquarters
Utrecht
Parent
SURF (Samenwerkende Universitaire Rekenfaciliteiten)

Network profile

Source: PeeringDB →
Network type Educational/Research
Geographic scope Not Disclosed
Traffic ratio Not Disclosed
Peering policy Open
IRR record AS-NOTSURFNET

Present at 4 internet exchanges: AMS-IX, Frys-IX, Speed-IX: SPEED-IX, NL-ix: Main

Top CIDR ranges

CIDRIPsPTR DensityOrganizationCountryStateCity
145.192.0.0/12 1.05M
99.8%
SURF B.V. NL
145.208.0.0/13 524.3K
97.7%
SURF B.V. NL
145.216.0.0/15 131.1K
95.3%
SURF B.V. NL
44.137.0.0/16 65.5K
6.2%
SURF B.V. US
145.99.0.0/16 65.5K
0.0%
SURF B.V. NL
145.220.0.0/16 65.5K
91.4%
SURF B.V. NL
192.42.128.0/22 1.0K
2.4%
SURF B.V. NL
145.102.4.0/23 512
0.0%
SURF B.V. NL
192.42.118.0/23 512
1.8%
SURF B.V. NL
185.17.73.0/24 256
17.6%
SURF B.V. NL
185.100.59.0/24 256
93.8%
SURF B.V. NL
192.12.54.0/24 256
10.2%
SURF B.V. NL
192.16.200.0/24 256
0.0%
SURF B.V. NL
192.42.117.0/24 256
1.6%
SURF B.V. NL
192.150.94.0/24 256
14.8%
SURF B.V. NL

BGP Announced Prefixes

Live BGP anomalies →

Prefixes AS1101 actually originates in BGP, observed across our RIPE RIS collectors. This live routing view can differ from the registry allocation above.

PrefixAnnouncement samplesLast seen
145.102.4.0/23 27,691 2026-07-23 21:24:11
145.99.0.0/16 27,477 2026-07-23 21:24:11
185.100.59.0/24 21,312 2026-07-23 21:24:11
145.192.0.0/12 12,465 2026-07-23 21:24:11
145.220.0.0/16 12,358 2026-07-23 21:24:11
145.208.0.0/13 12,106 2026-07-23 21:24:11
145.216.0.0/15 12,031 2026-07-23 21:24:11
44.137.0.0/16 9,629 2026-07-23 21:25:11
192.12.54.0/24 8,937 2026-07-23 21:24:11
192.42.117.0/24 8,805 2026-07-23 21:24:11
192.150.94.0/24 8,647 2026-07-23 21:24:11
192.42.128.0/22 8,634 2026-07-23 21:24:11
192.16.200.0/24 8,572 2026-07-23 21:24:11
185.17.73.0/24 6,631 2026-07-23 21:24:11
192.42.118.0/23 5,446 2026-07-23 21:24:12
192.42.119.0/24 2,606 2026-07-23 20:47:48
192.42.118.0/24 2,601 2026-07-23 20:47:48

Frequently Asked Questions

What is AS1101?

AS1101 is an Autonomous System Number assigned to SURF B.V.. 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 AS1101 announce?

AS1101 announces 1.90M IPv4 addresses distributed across 15 routed CIDR prefixes. The network is registered in The Netherlands.

Who operates AS1101?

AS1101 is operated by SURF B.V.. The organization is based in The Netherlands. You can view all IP ranges and related ASNs on the organization page.

What country is AS1101 registered in?

AS1101 is registered in The Netherlands. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.

Last updated: 2026-07-23 21:25:31 UTC
Share