Autonomous System

AS1103

SURF B.V.

SURF B.V. The Netherlands 🌐 surf.nl

Announced IPs

7,195,392

CIDR prefixes

125

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 v1.3.0 — 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	2026-11-11 15:38:52

Network profile

Source: PeeringDB →

Network type Educational/Research

Traffic level 500-1000Gbps

Geographic scope Europe

Traffic ratio Mostly Inbound

Peering policy Open

IRR record RIPE::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
145.144.0.0/12	1.05M	86.4%	SURF B.V.	NL	Gelderland	Breedenbroek
145.160.0.0/12	1.05M	99.8%	SURF B.V.	NL	—	—
145.88.0.0/14	262.1K	19.8%	SURF B.V.	NL	South Holland	Leiden
145.120.0.0/14	262.1K	49.9%	SURF B.V.	NL	Utrecht	Zeist
145.140.0.0/14	262.1K	99.0%	SURF B.V.	NL	Utrecht	Utrecht
145.2.0.0/15	131.1K	28.7%	SURF B.V.	NL	Overijssel	Wierden
145.28.0.0/15	131.1K	15.9%	SURF B.V.	NL	North Holland	Stompetoren
145.38.0.0/15	131.1K	1.5%	SURF B.V.	NL	—	—
145.48.0.0/15	131.1K	0.0%	SURF B.V.	NL	North Brabant	Tilburg
145.74.0.0/15	131.1K	14.6%	SURF B.V.	NL	Gelderland	Nijmegen
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	58.5%	SURF B.V.	NL	South Holland	Rotterdam
129.125.0.0/16	65.5K	31.3%	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	12.0%	SURF B.V.	NL	Gelderland	Nijmegen
131.211.0.0/16	65.5K	17.7%	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	10.8%	SURF B.V.	NL	South Holland	Voorburg
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	48.9%	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	17.7%	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	1.1%	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	28.2%	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	29.7%	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	20.3%	SURF B.V.	NL	South Holland	Rotterdam
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	Overijssel	Zwolle
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	61.1%	SURF B.V.	NL	North Holland	Amsterdam
145.85.0.0/16	65.5K	0.2%	SURF B.V.	NL	North Brabant	Tilburg
145.95.0.0/16	65.5K	0.0%	SURF B.V.	NL	—	—
145.96.0.0/16	65.5K	99.6%	SURF B.V.	NL	—	—
145.101.0.0/16	65.5K	66.5%	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	58.9%	SURF B.V.	NL	North Holland	Amsterdam
145.117.0.0/16	65.5K	99.4%	SURF B.V.	NL	North Holland	Amsterdam
145.118.0.0/16	65.5K	49.6%	SURF B.V.	NL	Zeeland	Colijnsplaat
145.126.0.0/16	65.5K	44.7%	SURF B.V.	NL	Overijssel	Enschede
145.138.0.0/16	65.5K	74.6%	SURF B.V.	NL	Gelderland	Nijmegen
156.83.0.0/16	65.5K	1.5%	SURF B.V.	NL	South Holland	Rotterdam
192.87.0.0/16	65.5K	49.7%	SURF B.V.	NL	Groningen	Haren
194.171.0.0/16	65.5K	52.7%	SURF B.V.	NL	Utrecht	Utrecht
195.169.0.0/16	65.5K	27.8%	SURF B.V.	NL	North Holland	Beverwijk
145.1.0.0/17	32.8K	0.1%	SURF B.V.	NL	North Holland	Den Burg
145.9.128.0/17	32.8K	0.0%	SURF B.V.	NL	—	—
145.97.128.0/17	32.8K	95.8%	SURF B.V.	NL	Groningen	Groningen
145.98.128.0/17	32.8K	99.4%	SURF B.V.	NL	—	—
145.100.128.0/17	32.8K	45.3%	SURF B.V.	NL	North Brabant	Geldrop
145.102.128.0/17	32.8K	43.6%	SURF B.V.	NL	North Brabant	Tilburg
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	Vaals
192.87.0.0/17	32.8K	56.1%	SURF B.V.	NL	Groningen	Haren
194.171.128.0/17	32.8K	58.5%	SURF B.V.	NL	Friesland	Stiens
145.9.64.0/18	16.4K	0.0%	SURF B.V.	NL	—	—
145.97.64.0/18	16.4K	0.2%	SURF B.V.	NL	Overijssel	Hengelo
145.98.64.0/18	16.4K	4.1%	SURF B.V.	NL	—	—
145.100.0.0/18	16.4K	14.2%	SURF B.V.	NL	North Holland	Amsterdam
145.102.64.0/18	16.4K	63.7%	SURF B.V.	NL	Utrecht	Soest
145.102.192.0/18	16.4K	37.3%	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
192.87.192.0/18	16.4K	49.7%	SURF B.V.	NL	South Holland	Rotterdam
194.171.0.0/18	16.4K	47.5%	SURF B.V.	NL	Gelderland	Doetinchem
145.9.32.0/19	8.2K	0.0%	SURF B.V.	NL	—	—
145.97.0.0/19	8.2K	31.3%	SURF B.V.	NL	Gelderland	Nijmegen
145.98.32.0/19	8.2K	99.5%	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 Brabant	Tilburg
145.107.32.0/19	8.2K	25.2%	SURF B.V.	NL	North Brabant	Tilburg
145.116.224.0/19	8.2K	0.0%	SURF B.V.	NL	Overijssel	Vriezenveen
192.87.128.0/19	8.2K	42.4%	SURF B.V.	NL	North Holland	Amsterdam
194.171.64.0/19	8.2K	35.8%	SURF B.V.	NL	Groningen	Groningen
145.9.0.0/20	4.1K	0.0%	SURF B.V.	NL	—	—
145.97.48.0/20	4.1K	0.0%	SURF B.V.	NL	Overijssel	Hengelo
145.98.16.0/20	4.1K	93.0%	SURF B.V.	NL	—	—
145.100.96.0/20	4.1K	19.0%	SURF B.V.	NL	North Holland	Amsterdam
145.102.16.0/20	4.1K	51.7%	SURF B.V.	NL	Gelderland	Nijmegen
145.102.144.0/20	4.1K	99.5%	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	15.3%	SURF B.V.	NL	—	—
192.87.176.0/20	4.1K	13.2%	SURF B.V.	NL	North Brabant	Best
194.13.16.0/20	4.1K	0.0%	SURF B.V.	NL	—	—
194.104.240.0/20	4.1K	0.0%	SURF B.V.	NL	—	—
194.171.112.0/20	4.1K	71.1%	SURF B.V.	NL	—	—
145.9.24.0/21	2.0K	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
192.31.231.0/24	88,473	2026-11-11 15:24:53
130.37.0.0/16	85,974	2026-11-11 15:24:50
145.108.0.0/16	85,489	2026-11-11 15:24:50
145.20.0.0/16	83,000	2026-11-11 15:24:50
192.33.36.0/24	79,117	2026-11-11 15:24:53
145.97.16.0/22	76,183	2026-11-11 15:24:50
145.81.0.0/16	74,081	2026-11-11 15:24:50
194.104.240.0/20	72,508	2026-11-11 15:24:53
194.26.12.0/22	72,404	2026-11-11 15:24:53
194.26.8.0/22	72,319	2026-11-11 15:24:52
145.91.0.0/16	72,072	2026-11-11 15:24:53
136.231.0.0/16	69,629	2026-11-11 15:24:50
145.98.16.0/24	69,512	2026-11-11 15:24:50
192.42.124.0/22	66,760	2026-11-11 15:24:50
145.100.0.0/15	66,377	2026-11-11 15:24:52
145.1.0.0/17	66,329	2026-11-11 15:24:50
145.44.0.0/16	66,285	2026-11-11 15:24:50
145.102.0.0/16	66,046	2026-11-11 15:24:52
145.38.0.0/15	65,348	2026-11-11 15:24:52
145.118.0.0/16	65,310	2026-11-11 15:24:52
145.140.0.0/14	65,195	2026-11-11 15:24:50
193.176.235.0/24	64,936	2026-11-11 15:24:50
145.9.0.0/16	64,684	2026-11-11 15:24:50
145.97.24.0/21	64,198	2026-11-11 15:24:50
145.107.24.0/22	64,174	2026-11-11 15:24:50
132.229.0.0/16	64,074	2026-11-11 15:24:50
145.116.64.0/18	63,836	2026-11-11 15:24:50
145.97.0.0/20	63,809	2026-11-11 15:24:50
137.224.0.0/16	63,800	2026-11-11 15:24:50
129.125.0.0/16	63,447	2026-11-11 15:21:38
145.124.0.0/15	63,443	2026-11-11 15:24:52
145.97.128.0/18	63,279	2026-11-11 15:21:38
145.97.20.0/22	63,150	2026-11-11 15:24:50
156.83.0.0/16	62,571	2026-11-11 15:24:50
145.41.0.0/16	62,561	2026-11-11 15:24:50
194.104.124.0/23	62,438	2026-11-11 15:24:53
145.51.0.0/16	62,303	2026-11-11 15:24:53
145.97.48.0/20	62,176	2026-11-11 15:24:50
131.224.0.0/16	62,173	2026-11-11 15:24:52
145.24.0.0/16	61,998	2026-11-11 15:24:53
145.126.0.0/16	61,809	2026-11-11 15:24:52
193.177.176.0/22	61,519	2026-11-11 15:24:53
195.169.0.0/16	61,451	2026-11-11 15:24:52
145.48.0.0/15	61,199	2026-11-11 15:24:52
194.171.0.0/16	61,168	2026-11-11 15:24:52
141.252.0.0/16	61,120	2026-11-11 15:24:53
145.137.128.0/18	60,659	2026-11-11 15:24:50
145.92.0.0/15	60,391	2026-11-11 15:24:52
145.98.0.0/16	60,321	2026-11-11 15:24:52
145.117.0.0/16	60,307	2026-11-11 15:24:50

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 7.20M IPv4 addresses distributed across 125 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: 2026-11-11 15:39:06 UTC