Autonomous System

AS1103

SURF B.V.

SURF B.V. The Netherlands 🌐 surf.nl

Announced IPs

6,665,984

CIDR prefixes

124

ASN

AS1103

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.

57/100

Caution

How this score is built

Baseline (neutral) 65
Active-threat / abuse risk −12
Enterprise allocation +4
Trust score 57 / 100

Experimental · trust-vectors model v1.2.1 — 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)

Official website ↗ Summary from Wikipedia, CC BY-SA 4.0 · Data from Wikidata

⚠ 1 MOAS prefix — multiple origin ASNs detected

All MOAS anomalies →

A previously stable prefix originated by AS1103 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.

Prefix	Origin ASNs	Last detected (UTC)
145.98.16.0/24	AS1103, AS1653	2026-10-01 18:26:59

Network profile

Source: PeeringDB →

Network type Educational/Research

Traffic level 500-1000Gbps

Geographic scope Europe

Traffic ratio Mostly Inbound

Peering policy Open

IRR record AS1103:AS-SURF

Present at 3 internet exchanges: NL-ix: Main, AMS-IX, Frys-IX

Website ↗

Top CIDR ranges

CIDR	IPs	PTR Density	Organization	Country	State	City
145.160.0.0/12	1.05M	99.3%	SURF B.V.	NL	—	—
145.144.0.0/13	524.3K	72.8%	SURF B.V.	NL	Gelderland	Breedenbroek
145.88.0.0/14	262.1K	19.6%	SURF B.V.	NL	South Holland	Leiden
145.120.0.0/14	262.1K	49.8%	SURF B.V.	NL	Utrecht	Houten
145.140.0.0/14	262.1K	98.5%	SURF B.V.	NL	South Holland	Capelle aan den IJssel
145.2.0.0/15	131.1K	28.6%	SURF B.V.	NL	Overijssel	Deventer
145.28.0.0/15	131.1K	15.8%	SURF B.V.	NL	North Holland	Stompetoren
145.38.0.0/15	131.1K	1.4%	SURF B.V.	NL	—	—
145.48.0.0/15	131.1K	0.0%	SURF B.V.	NL	North Brabant	Made
145.74.0.0/15	131.1K	14.6%	SURF B.V.	NL	Gelderland	Arnhem
145.92.0.0/15	131.1K	6.9%	SURF B.V.	NL	North Brabant	Eindhoven
145.124.0.0/15	131.1K	0.2%	SURF B.V.	NL	—	—
145.136.0.0/15	131.1K	58.3%	SURF B.V.	NL	South Holland	Rotterdam
145.216.0.0/15	131.1K	99.3%	SURF B.V.	NL	—	—
129.125.0.0/16	65.5K	30.7%	SURF B.V.	NL	Groningen	Groningen
130.37.0.0/16	65.5K	14.1%	SURF B.V.	NL	North Holland	Amsterdam
131.174.0.0/16	65.5K	12.3%	SURF B.V.	NL	Gelderland	Nijmegen
131.211.0.0/16	65.5K	19.7%	SURF B.V.	NL	Utrecht	Utrecht
131.224.0.0/16	65.5K	0.8%	SURF B.V.	NL	Utrecht	De Bilt
132.229.0.0/16	65.5K	10.9%	SURF B.V.	NL	South Holland	Leiden
134.221.0.0/16	65.5K	3.2%	SURF B.V.	NL	—	—
136.231.0.0/16	65.5K	11.7%	SURF B.V.	NL	South Holland	Delfgauw
137.56.0.0/16	65.5K	48.8%	SURF B.V.	NL	North Brabant	Tilburg
137.120.0.0/16	65.5K	1.9%	SURF B.V.	NL	Limburg	Maastricht
137.224.0.0/16	65.5K	0.8%	SURF B.V.	NL	Gelderland	Wageningen
139.63.0.0/16	65.5K	16.7%	SURF B.V.	NL	South Holland	The Hague
141.252.0.0/16	65.5K	0.1%	SURF B.V.	NL	Friesland	Leeuwarden
143.121.0.0/16	65.5K	1.2%	SURF B.V.	NL	Utrecht	Utrecht
145.0.0.0/16	65.5K	0.4%	SURF B.V.	NL	North Holland	Amsterdam
145.5.0.0/16	65.5K	28.1%	SURF B.V.	NL	South Holland	Rotterdam
145.9.0.0/16	65.5K	0.0%	SURF B.V.	NL	—	—
145.19.0.0/16	65.5K	29.6%	SURF B.V.	NL	Zeeland	Flushing
145.20.0.0/16	65.5K	8.2%	SURF B.V.	NL	—	—
145.23.0.0/16	65.5K	0.1%	SURF B.V.	NL	Utrecht	Bilthoven
145.24.0.0/16	65.5K	20.2%	SURF B.V.	NL	North Holland	Egmond aan den Hoef
145.33.0.0/16	65.5K	0.2%	SURF B.V.	NL	Groningen	Groningen
145.37.0.0/16	65.5K	0.0%	SURF B.V.	NL	Groningen	Groningen
145.41.0.0/16	65.5K	0.0%	SURF B.V.	NL	—	—
145.44.0.0/16	65.5K	38.5%	SURF B.V.	NL	Gelderland	Nunspeet
145.51.0.0/16	65.5K	0.6%	SURF B.V.	NL	—	—
145.52.0.0/16	65.5K	1.9%	SURF B.V.	NL	South Holland	The Hague
145.76.0.0/16	65.5K	0.1%	SURF B.V.	NL	Overijssel	Enschede
145.81.0.0/16	65.5K	60.7%	SURF B.V.	NL	North Holland	Vijfhuizen
145.85.0.0/16	65.5K	0.2%	SURF B.V.	NL	North Brabant	Eindhoven
145.95.0.0/16	65.5K	0.0%	SURF B.V.	NL	—	—
145.96.0.0/16	65.5K	99.4%	SURF B.V.	NL	—	—
145.101.0.0/16	65.5K	65.7%	SURF B.V.	NL	North Brabant	Breda
145.103.0.0/16	65.5K	99.4%	SURF B.V.	NL	South Holland	The Hague
145.108.0.0/16	65.5K	54.9%	SURF B.V.	NL	North Holland	Amsterdam
145.117.0.0/16	65.5K	99.1%	SURF B.V.	NL	North Holland	Amsterdam
145.118.0.0/16	65.5K	49.4%	SURF B.V.	NL	Zeeland	Colijnsplaat
145.126.0.0/16	65.5K	44.6%	SURF B.V.	NL	Overijssel	Enschede
145.138.0.0/16	65.5K	74.1%	SURF B.V.	NL	Gelderland	Nijmegen
156.83.0.0/16	65.5K	1.5%	SURF B.V.	NL	South Holland	Rotterdam
194.171.0.0/16	65.5K	52.8%	SURF B.V.	NL	South Holland	Zoetermeer
195.169.0.0/16	65.5K	27.8%	SURF B.V.	NL	North Holland	Hoofddorp
145.1.0.0/17	32.8K	0.1%	SURF B.V.	NL	North Holland	Den Burg
145.97.128.0/17	32.8K	95.4%	SURF B.V.	NL	Groningen	Groningen
145.98.128.0/17	32.8K	99.2%	SURF B.V.	NL	—	—
145.100.128.0/17	32.8K	45.0%	SURF B.V.	NL	North Brabant	Eindhoven
145.107.128.0/17	32.8K	0.4%	SURF B.V.	NL	Utrecht	Utrecht
145.127.0.0/17	32.8K	99.4%	SURF B.V.	NL	Limburg	Vaals
192.87.0.0/17	32.8K	56.6%	SURF B.V.	NL	Groningen	Groningen
194.171.128.0/17	32.8K	58.5%	SURF B.V.	NL	South Holland	Zoetermeer
145.97.64.0/18	16.4K	0.2%	SURF B.V.	NL	Overijssel	Enschede
145.98.64.0/18	16.4K	3.6%	SURF B.V.	NL	—	—
145.100.0.0/18	16.4K	14.1%	SURF B.V.	NL	North Holland	Amsterdam
145.102.64.0/18	16.4K	63.5%	SURF B.V.	NL	North Holland	Amsterdam
145.102.192.0/18	16.4K	37.2%	SURF B.V.	NL	Gelderland	Nijmegen
145.107.64.0/18	16.4K	0.0%	SURF B.V.	NL	Utrecht	Utrecht
145.116.64.0/18	16.4K	0.0%	SURF B.V.	NL	South Holland	The Hague
145.116.128.0/18	16.4K	0.0%	SURF B.V.	NL	North Brabant	Mierlo
192.87.192.0/18	16.4K	49.8%	SURF B.V.	NL	North Holland	Amsterdam
194.171.0.0/18	16.4K	47.6%	SURF B.V.	NL	North Holland	Amsterdam
145.97.0.0/19	8.2K	31.2%	SURF B.V.	NL	Gelderland	Nijmegen
145.98.32.0/19	8.2K	99.3%	SURF B.V.	NL	—	—
145.100.64.0/19	8.2K	24.9%	SURF B.V.	NL	North Holland	Amsterdam
145.102.32.0/19	8.2K	0.5%	SURF B.V.	NL	South Holland	Leiden
145.102.160.0/19	8.2K	0.4%	SURF B.V.	NL	North Brabant	Breda
145.107.32.0/19	8.2K	24.9%	SURF B.V.	NL	North Brabant	Heibloem
145.116.224.0/19	8.2K	0.0%	SURF B.V.	NL	Overijssel	Hengelo
192.87.128.0/19	8.2K	42.5%	SURF B.V.	NL	North Holland	Amsterdam
194.171.64.0/19	8.2K	35.9%	SURF B.V.	NL	Groningen	Groningen
145.97.48.0/20	4.1K	0.0%	SURF B.V.	NL	Overijssel	Hengelo
145.98.16.0/20	4.1K	93.2%	SURF B.V.	NL	—	—
145.100.96.0/20	4.1K	18.8%	SURF B.V.	NL	North Holland	Amsterdam
145.102.16.0/20	4.1K	51.7%	SURF B.V.	NL	Gelderland	Hengelo
145.102.144.0/20	4.1K	99.2%	SURF B.V.	NL	North Brabant	Eindhoven
145.107.16.0/20	4.1K	0.0%	SURF B.V.	NL	—	—
145.116.192.0/20	4.1K	17.3%	SURF B.V.	NL	—	—
192.87.176.0/20	4.1K	13.2%	SURF B.V.	NL	North Brabant	Best
194.104.240.0/20	4.1K	0.0%	SURF B.V.	NL	—	—
194.171.112.0/20	4.1K	71.4%	SURF B.V.	NL	—	—
145.98.8.0/21	2.0K	99.5%	SURF B.V.	NL	—	—
145.100.120.0/21	2.0K	0.0%	SURF B.V.	NL	—	—
145.102.8.0/21	2.0K	99.4%	SURF B.V.	NL	—	—
145.102.128.0/21	2.0K	98.6%	SURF B.V.	NL	—	—
145.107.8.0/21	2.0K	0.9%	SURF B.V.	NL	—	—
192.87.168.0/21	2.0K	47.1%	SURF B.V.	NL	—	—
194.13.112.0/21	2.0K	1.1%	SURF B.V.	NL	Utrecht	Utrecht

BGP Announced Prefixes

Live BGP anomalies →

Prefixes AS1103 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
145.20.0.0/16	66,660	2026-10-01 17:11:09
145.97.16.0/22	60,585	2026-10-01 17:11:09
145.81.0.0/16	60,225	2026-10-01 17:11:09
194.104.240.0/20	59,762	2026-10-01 15:23:42
145.91.0.0/16	59,522	2026-10-01 15:23:42
194.26.12.0/22	56,903	2026-10-01 15:23:41
194.26.8.0/22	55,809	2026-10-01 15:23:33
130.37.0.0/16	54,546	2026-10-01 16:19:54
145.108.0.0/16	54,172	2026-10-01 16:19:54
192.31.231.0/24	54,075	2026-10-01 15:23:42
192.42.124.0/22	53,556	2026-10-01 17:11:09
136.231.0.0/16	53,353	2026-10-01 17:11:09
145.100.0.0/15	52,817	2026-10-01 15:23:13
145.102.0.0/16	52,695	2026-10-01 15:23:33
145.33.0.0/16	52,436	2026-10-01 17:11:10
145.38.0.0/15	52,329	2026-10-01 15:23:13
145.37.0.0/16	52,200	2026-10-01 17:11:10
145.118.0.0/16	51,958	2026-10-01 15:23:33
129.125.0.0/16	51,907	2026-10-01 16:30:31
145.97.128.0/18	51,687	2026-10-01 16:30:31
132.229.0.0/16	50,885	2026-10-01 17:11:09
145.1.0.0/17	50,823	2026-10-01 17:11:09
145.116.64.0/18	50,785	2026-10-01 17:11:09
131.224.0.0/16	50,743	2026-10-01 15:23:33
137.224.0.0/16	50,733	2026-10-01 17:11:09
145.97.0.0/20	50,645	2026-10-01 17:11:09
145.97.24.0/21	50,545	2026-10-01 17:11:09
145.97.20.0/22	50,461	2026-10-01 17:11:09
145.44.0.0/16	50,363	2026-10-01 17:11:09
145.107.24.0/22	50,164	2026-10-01 17:11:09
145.103.0.0/16	49,912	2026-10-01 15:23:39
145.97.48.0/20	49,831	2026-10-01 17:11:09
145.124.0.0/15	49,755	2026-10-01 15:23:13
145.48.0.0/15	49,752	2026-10-01 15:23:13
145.51.0.0/16	49,703	2026-10-01 15:23:42
145.98.0.0/16	49,576	2026-10-01 15:23:33
145.41.0.0/16	49,567	2026-10-01 17:11:09
145.24.0.0/16	49,477	2026-10-01 15:23:42
156.83.0.0/16	49,467	2026-10-01 17:11:09
194.104.124.0/23	49,418	2026-10-01 15:23:42
145.98.16.0/24	49,355	2026-10-01 18:32:24
193.177.176.0/22	48,972	2026-10-01 15:23:41
193.176.235.0/24	48,712	2026-10-01 17:11:09
141.252.0.0/16	48,591	2026-10-01 15:23:42
195.169.0.0/16	48,522	2026-10-01 15:23:33
145.126.0.0/16	48,484	2026-10-01 15:23:33
145.9.0.0/16	48,414	2026-10-01 17:11:09
145.140.0.0/14	47,998	2026-10-01 15:23:22
194.171.0.0/16	47,922	2026-10-01 15:23:33
131.174.0.0/16	47,902	2026-10-01 15:23:33

Showing top 50 of 106 announced prefixes by sample volume.

Frequently Asked Questions

What is AS1103?

AS1103 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 AS1103 announce?

AS1103 announces 6.67M IPv4 addresses distributed across 124 routed CIDR prefixes. The network is registered in The Netherlands.

Who operates AS1103?

AS1103 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 AS1103 registered in?

AS1103 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: 2026-10-01 18:54:04 UTC