Autonomous System

AS1103

SURF B.V.

SURF B.V. The Netherlands 🌐 surf.nl

Announced IPs

7,195,648

CIDR prefixes

120

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
Multiple-origin (MOAS) routing anomaly −12
Enterprise allocation +4
Trust score 57 / 100

Experimental · trust-vectors model v1.1.0 — 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)

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	2026-07-18 12:37:44

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 ↗

AS1103 — global IP footprint

Cities where AS1103 has measurable IPv4 allocation. Click any dot to open that city's page. Size and color scale with IP count.

View on 3D globe →

Top CIDR ranges

CIDR	IPs	PTR Density	Organization	Country	State	City
145.144.0.0/12	1.05M	86.5%	SURF B.V.	NL	Gelderland	Wehl
145.160.0.0/12	1.05M	0.0%	SURF B.V.	NL	—	—
145.144.0.0/13	524.3K	73.1%	SURF B.V.	NL	Gelderland	Wehl
145.88.0.0/14	262.1K	18.5%	SURF B.V.	NL	South Holland	Leiden
145.120.0.0/14	262.1K	50.0%	SURF B.V.	NL	Gelderland	Barneveld
145.140.0.0/14	262.1K	75.0%	SURF B.V.	NL	South Holland	Rotterdam
145.148.0.0/14	262.1K	0.0%	—	NL	—	—
145.2.0.0/15	131.1K	25.2%	SURF B.V.	NL	Overijssel	Deventer
145.28.0.0/15	131.1K	10.8%	SURF B.V.	NL	North Holland	Spierdijk
145.38.0.0/15	131.1K	1.3%	SURF B.V.	NL	—	—
145.48.0.0/15	131.1K	0.0%	SURF B.V.	NL	North Brabant	Oosterhout
145.74.0.0/15	131.1K	14.7%	SURF B.V.	NL	Gelderland	Nijmegen
145.92.0.0/15	131.1K	0.0%	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	57.9%	SURF B.V.	NL	South Holland	Rotterdam
129.125.0.0/16	65.5K	32.7%	SURF B.V.	NL	Groningen	Groningen
130.37.0.0/16	65.5K	14.0%	SURF B.V.	NL	North Holland	Amsterdam
131.174.0.0/16	65.5K	5.4%	SURF B.V.	NL	Gelderland	Wijchen
131.211.0.0/16	65.5K	19.6%	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	10.2%	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	11.8%	SURF B.V.	NL	South Holland	Delft
137.56.0.0/16	65.5K	48.7%	SURF B.V.	NL	North Brabant	Tilburg
137.120.0.0/16	65.5K	1.8%	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	11.2%	SURF B.V.	NL	South Holland	Delft
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	29.1%	SURF B.V.	NL	Zeeland	Flushing
145.20.0.0/16	65.5K	5.1%	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	18.4%	SURF B.V.	NL	North Holland	Egmond aan den Hoef
145.33.0.0/16	65.5K	0.2%	SURF B.V.	NL	Groningen	Hoogezand
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	38.7%	SURF B.V.	NL	Overijssel	Ommen
145.51.0.0/16	65.5K	0.6%	SURF B.V.	NL	—	—
145.52.0.0/16	65.5K	1.8%	SURF B.V.	NL	South Holland	The Hague
145.76.0.0/16	65.5K	0.1%	SURF B.V.	NL	Overijssel	Hengelo
145.81.0.0/16	65.5K	61.1%	SURF B.V.	NL	North Holland	Amsterdam
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	98.5%	SURF B.V.	NL	—	—
145.101.0.0/16	65.5K	66.1%	SURF B.V.	NL	North Brabant	Breda
145.103.0.0/16	65.5K	100.0%	SURF B.V.	NL	South Holland	The Hague
145.108.0.0/16	65.5K	89.8%	SURF B.V.	NL	North Holland	Amstelveen
145.117.0.0/16	65.5K	100.0%	SURF B.V.	NL	North Holland	Amsterdam
145.118.0.0/16	65.5K	49.9%	SURF B.V.	NL	South Holland	Leiden
145.126.0.0/16	65.5K	45.0%	SURF B.V.	NL	Overijssel	Enschede
145.138.0.0/16	65.5K	74.6%	SURF B.V.	NL	Overijssel	Raalte
145.144.0.0/16	65.5K	0.0%	—	NL	Gelderland	Wehl
145.147.0.0/16	65.5K	0.0%	—	NL	—	—
156.83.0.0/16	65.5K	1.5%	SURF B.V.	NL	South Holland	Rotterdam
192.87.0.0/16	65.5K	49.8%	SURF B.V.	NL	North Holland	Amsterdam
194.171.0.0/16	65.5K	0.0%	—	NL	Utrecht	Utrecht
195.169.0.0/16	65.5K	25.4%	SURF B.V.	NL	Utrecht	Amersfoort
145.1.0.0/17	32.8K	0.0%	SURF B.V.	NL	North Holland	Den Hoorn
145.97.128.0/17	32.8K	96.0%	SURF B.V.	NL	Groningen	Groningen
145.98.128.0/17	32.8K	100.0%	SURF B.V.	NL	—	—
145.100.128.0/17	32.8K	45.4%	SURF B.V.	NL	Limburg	Venlo
145.107.128.0/17	32.8K	0.4%	SURF B.V.	NL	Utrecht	Utrecht
145.127.0.0/17	32.8K	100.0%	SURF B.V.	NL	Limburg	Maastricht
145.145.0.0/17	32.8K	0.0%	—	NL	—	—
145.146.128.0/17	32.8K	0.0%	—	NL	—	—
194.171.128.0/17	32.8K	50.2%	SURF B.V.	NL	Utrecht	Utrecht
145.97.64.0/18	16.4K	74.9%	SURF B.V.	NL	Overijssel	Saasveld
145.98.64.0/18	16.4K	0.3%	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	64.1%	SURF B.V.	NL	North Holland	Amsterdam
145.102.192.0/18	16.4K	37.5%	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	Gelderland	Nijmegen
145.145.192.0/18	16.4K	0.0%	—	NL	—	—
145.146.64.0/18	16.4K	0.0%	—	NL	—	—
194.171.0.0/18	16.4K	42.7%	SURF B.V.	NL	North Holland	Amsterdam
145.97.0.0/19	8.2K	31.3%	SURF B.V.	NL	Gelderland	Nijmegen
145.98.32.0/19	8.2K	100.0%	SURF B.V.	NL	—	—
145.100.64.0/19	8.2K	25.0%	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 Holland	Beverwijk
145.107.32.0/19	8.2K	25.2%	SURF B.V.	NL	Limburg	Horst aan de Maas Municipality
145.116.224.0/19	8.2K	0.0%	SURF B.V.	NL	Overijssel	Borne
145.145.128.0/19	8.2K	0.0%	—	NL	—	—
145.146.32.0/19	8.2K	0.0%	—	NL	—	—
194.171.64.0/19	8.2K	32.0%	SURF B.V.	NL	South Holland	Leiden
145.97.48.0/20	4.1K	94.2%	SURF B.V.	NL	Overijssel	Vroomshoop
145.98.16.0/20	4.1K	93.7%	SURF B.V.	NL	—	—
145.100.96.0/20	4.1K	16.9%	SURF B.V.	NL	North Holland	Amsterdam
145.102.16.0/20	4.1K	51.1%	SURF B.V.	NL	—	—
145.102.144.0/20	4.1K	100.0%	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	11.6%	SURF B.V.	NL	—	—
145.145.176.0/20	4.1K	0.0%	—	NL	—	—
145.146.16.0/20	4.1K	0.0%	—	NL	—	—
194.13.16.0/20	4.1K	0.0%	SURF B.V.	NL	—	—

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
145.81.0.0/16	25,576	2026-07-18 12:28:25
145.20.0.0/16	22,141	2026-07-18 12:28:25
136.231.0.0/16	20,546	2026-07-18 12:28:25
145.33.0.0/16	19,256	2026-07-18 12:28:33
145.37.0.0/16	19,064	2026-07-18 12:28:33
145.100.0.0/15	18,909	2026-07-18 12:28:23
145.102.0.0/16	18,868	2026-07-18 12:28:23
131.224.0.0/16	18,766	2026-07-18 12:28:23
145.38.0.0/15	18,562	2026-07-18 12:28:23
192.42.124.0/22	18,491	2026-07-18 12:28:25
132.229.0.0/16	18,489	2026-07-18 12:28:25
145.97.0.0/20	18,415	2026-07-18 12:28:25
137.224.0.0/16	18,403	2026-07-18 12:28:25
145.97.24.0/21	18,379	2026-07-18 12:28:25
145.97.20.0/22	18,375	2026-07-18 12:28:25
145.116.64.0/18	18,374	2026-07-18 12:28:25
145.97.16.0/22	18,343	2026-07-18 12:28:25
145.98.0.0/16	18,339	2026-07-18 12:28:22
145.96.0.0/16	18,293	2026-07-18 12:28:23
145.44.0.0/16	18,179	2026-07-18 12:28:25
145.107.0.0/16	18,136	2026-07-18 12:28:23
145.118.0.0/16	18,106	2026-07-18 12:28:23
131.174.0.0/16	17,987	2026-07-18 12:28:22
145.103.0.0/16	17,934	2026-07-18 12:28:33
145.107.24.0/22	17,854	2026-07-18 12:28:25
145.97.48.0/20	17,846	2026-07-18 12:28:25
145.48.0.0/15	17,667	2026-07-18 12:28:22
145.41.0.0/16	17,448	2026-07-18 12:28:25
130.37.0.0/16	17,312	2026-07-18 12:28:30
145.98.16.0/24	17,162	2026-07-18 12:28:25
145.108.0.0/16	17,147	2026-07-18 12:28:30
192.31.231.0/24	16,849	2026-07-18 12:28:30
194.104.124.0/23	16,827	2026-07-18 12:28:30
145.51.0.0/16	16,790	2026-07-18 12:28:29
194.104.240.0/20	16,751	2026-07-18 12:28:29
194.26.12.0/22	16,716	2026-07-18 12:28:29
193.176.235.0/24	16,689	2026-07-18 12:28:25
145.24.0.0/16	16,655	2026-07-18 12:28:29
145.91.0.0/16	16,632	2026-07-18 12:28:30
193.177.176.0/22	16,621	2026-07-18 12:28:29
141.252.0.0/16	16,535	2026-07-18 12:28:29
145.9.0.0/16	15,764	2026-07-18 12:28:25
145.124.0.0/15	15,763	2026-07-18 12:28:23
195.169.0.0/16	14,826	2026-07-18 12:28:23
145.137.128.0/18	14,760	2026-07-18 12:28:25
145.126.0.0/16	14,637	2026-07-18 12:28:23
145.95.0.0/16	14,247	2026-07-18 12:28:25
145.52.0.0/16	14,185	2026-07-18 12:28:25
194.171.0.0/16	14,184	2026-07-18 12:28:23
145.117.0.0/16	14,010	2026-07-18 12:28:25

Showing top 50 of 100 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 7.20M IPv4 addresses distributed across 120 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: 2026-07-18 12:40:28 UTC