ASN AS12303 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS12303?

AS12303 is listed under ISZT Nonprofit Kft..

What do peers, upstreams, and downstreams mean in ASN data?

Peers are lateral network interconnections, upstreams are transit providers, and downstreams are customer networks receiving connectivity.

What are routes and IP ranges for an ASN?

Routes and IP ranges are the network prefixes announced by the ASN on the internet and show the address space it originates.

Why is WHOIS data shown for an ASN?

WHOIS data provides registration and contact context for ASN ownership, administration, and operational reference.

How can I access the full ASN tables?

The page shows a preview of large ASN datasets. Use the page controls to load more rows, and upgrade to a paid plan for complete access.

AS12303 ISZT Nonprofit Kft. | IPGeolocation.io

ASN Lookup Tool

ISZT Nonprofit Kft. nic.hu

HU 2 Routes

AS Data

AS12303

AS12303 – ISZT Nonprofit Kft.

AS Number	12303
AS Name	ISZT-AS
Organization	ISZT Nonprofit Kft. (org-mist1-ripe)
Country	HU
Website	nic.hu
Number of IPv4 Routes	1
Number of IPv6 Routes	1
ASN type	ISP
Allocation Status	ASSIGNED
Registry	RIPE
Date Allocated	2005-06-14

ASN Intelligence API for production workflows

Use ASN data for AS12303 in automation: routing intelligence, peering analysis, ownership checks, and network observability.

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IP Ranges

Route	Origin	Origin Name	ISP	# IPs
5.28.0.0/22	AS12303	ISZT Nonprofit Kft.	ISZT Nonprofit Kft.	1024
2a00:e6a0::/40	AS12303	ISZT Nonprofit Kft.	Internet Szolgaltatok Tanacsa ISZT	~309×10²⁴

Raw Whois Response

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://docs.db.ripe.net/terms-conditions.html

% Note: this output has been filtered.
%       To receive output for a database update, use the "-B" flag.

% Information related to 'AS12288 - AS12454'

as-block:       AS12288 - AS12454
descr:          RIPE NCC ASN block
remarks:        These AS Numbers are assigned to network operators in the RIPE NCC service region.
mnt-by:         RIPE-NCC-HM-MNT
created:        2018-11-22T15:27:24Z
last-modified:  2018-11-22T15:27:24Z
source:         RIPE

% Information related to 'AS12303'

% Abuse contact for 'AS12303' is 'abuse@nic.hu'

aut-num:        AS12303
as-name:        ISZT-AS
descr:          ISZT Nonprofit Kft.
descr:          Blathy Otto utca 9.
descr:          H-1089 Budapest
descr:          Hungary
org:            ORG-MIST1-RIPE
remarks:        Upstreams
remarks:        ---------
mp-import:      afi ipv6.unicast from AS5507 accept AS-BIX-V6
mp-export:      afi ipv6.unicast to AS5507 announce AS-ISZT
mp-import:      afi ipv6.unicast from AS62214 accept ANY
mp-export:      afi ipv6.unicast to AS62214 announce AS-ISZT
mp-import:      afi ipv6.unicast from AS29278 accept ANY
mp-export:      afi ipv6.unicast to AS29278 announce AS-ISZT
import:         from AS5507 accept AS-BIX
export:         to AS5507 announce AS-ISZT
import:         from AS62214 accept ANY
export:         to AS62214 announce AS-ISZT
import:         from AS29278 accept ANY
export:         to AS29278 announce AS-ISZT
remarks:        Services
remarks:        --------
import:         from AS42909 accept { 194.0.1.0/24 }
import:         from AS42909 accept { 194.0.2.0/24 }
export:         to AS42909 announce AS-BIX
import:         from AS25152 accept { 193.0.14.0/24 }
export:         to AS25152 announce AS-BIX
import:         from AS1921 accept { 194.0.25.0/24 }
import:         from AS1921 accept { 192.174.68.0/24 }
import:         from AS1921 accept { 176.97.158.0/24 }
import:         from AS1921 accept { 91.237.67.0/24 }
import:         from AS1921 accept { 185.167.176.0/24 }
import:         from AS1921 accept { 193.227.117.0/24 }
import:         from AS1921 accept { 194.50.187.0/24 }
import:         from AS1921 accept { 194.0.182.0/24 }
import:         from AS1921 accept { 185.80.188.0/22 }
import:         from AS1921 accept { 193.46.128.0/22 }
import:         from AS1921 accept { 193.46.132.0/23 }
import:         from AS1921 accept { 193.46.134.0/24 }
import:         from AS1921 accept { 193.46.135.0/24 }
import:         from AS1921 accept { 194.0.26.0/24 }
import:         from AS1921 accept { 194.0.24.0/24 }
export:         to AS1921 announce AS-BIX
member-of:      AS3320:AS-AUTH-PILOT-BLACKHOLE-FROM-AS5483
admin-c:        JZ1170-RIPE
tech-c:         JZ1170-RIPE
status:         ASSIGNED
mnt-by:         RIPE-NCC-END-MNT
mnt-by:         HU-NIC-MNT
mnt-by:         AS5507-MNT
created:        2005-06-14T09:03:41Z
last-modified:  2026-06-22T11:18:49Z
source:         RIPE

organisation:   ORG-MIST1-RIPE
org-name:       Magyarorszagi Internet Szolgaltatok Tanacsa Tudomanyos Egyesulet
country:        HU
reg-nr:         01-02-0007581
org-type:       LIR
address:        Blathy Otto utca 9.
address:        1089
address:        Budapest
address:        HUNGARY
phone:          +36 30 626 6745
admin-c:        ANGE11-RIPE
tech-c:         ANGE11-RIPE
abuse-c:        AR56674-RIPE
mnt-ref:        AS5507-MNT
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         AS5507-MNT
created:        2019-11-12T11:19:14Z
last-modified:  2026-06-22T10:35:18Z
source:         RIPE # Filtered

person:         Janos Zsako
address:        ISZT Nonprofit Kft.
address:        Blathy Otto u. 9.
address:        1089 Budapest
address:        Hungary
phone:          +36 1 238 0115
nic-hdl:        JZ1170-RIPE
mnt-by:         ISZT-MNT
created:        2012-04-03T09:21:56Z
last-modified:  2026-04-10T13:02:33Z
source:         RIPE # Filtered

% This query was served by the RIPE Database Query Service version 1.123 (BUSA)

Parsed Whois Response

{
  "status" : true,
  "whois_server" : "whois.ripe.net",
  "as_blocks" : [ {
    "as_block" : "AS12288 - AS12454",
    "description" : [ "RIPE NCC ASN block" ],
    "remarks" : [ "These AS Numbers are assigned to network operators in the RIPE NCC service region." ],
    "mnt_by" : [ "RIPE-NCC-HM-MNT" ],
    "date_created" : "2018-11-22",
    "date_updated" : "2018-11-22",
    "source" : "RIPE"
  } ],
  "aut_nums" : [ {
    "aut_num" : "AS12303",
    "as_name" : "ISZT-AS",
    "description" : [ "ISZT Nonprofit Kft.", "Blathy Otto utca 9.", "H-1089 Budapest", "Hungary" ],
    "status" : "ASSIGNED",
    "member_of" : [ "AS3320:AS-AUTH-PILOT-BLACKHOLE-FROM-AS5483" ],
    "import" : [ "from AS5507 accept AS-BIX", "from AS62214 accept ANY", "from AS29278 accept ANY", "from AS42909 accept { 194.0.1.0/24 }", "from AS42909 accept { 194.0.2.0/24 }", "from AS25152 accept { 193.0.14.0/24 }", "from AS1921 accept { 194.0.25.0/24 }", "from AS1921 accept { 192.174.68.0/24 }", "from AS1921 accept { 176.97.158.0/24 }", "from AS1921 accept { 91.237.67.0/24 }", "from AS1921 accept { 185.167.176.0/24 }", "from AS1921 accept { 193.227.117.0/24 }", "from AS1921 accept { 194.50.187.0/24 }", "from AS1921 accept { 194.0.182.0/24 }", "from AS1921 accept { 185.80.188.0/22 }", "from AS1921 accept { 193.46.128.0/22 }", "from AS1921 accept { 193.46.132.0/23 }", "from AS1921 accept { 193.46.134.0/24 }", "from AS1921 accept { 193.46.135.0/24 }", "from AS1921 accept { 194.0.26.0/24 }", "from AS1921 accept { 194.0.24.0/24 }" ],
    "mp_import" : [ "afi ipv6.unicast from AS5507 accept AS-BIX-V6", "afi ipv6.unicast from AS62214 accept ANY", "afi ipv6.unicast from AS29278 accept ANY" ],
    "export" : [ "to AS5507 announce AS-ISZT", "to AS62214 announce AS-ISZT", "to AS29278 announce AS-ISZT", "to AS42909 announce AS-BIX", "to AS25152 announce AS-BIX", "to AS1921 announce AS-BIX" ],
    "mp_export" : [ "afi ipv6.unicast to AS5507 announce AS-ISZT", "afi ipv6.unicast to AS62214 announce AS-ISZT", "afi ipv6.unicast to AS29278 announce AS-ISZT" ],
    "organization" : "ORG-MIST1-RIPE",
    "admin_contacts" : [ "JZ1170-RIPE" ],
    "tech_contacts" : [ "JZ1170-RIPE" ],
    "remarks" : [ "Upstreams", "---------", "Services", "--------" ],
    "mnt_by" : [ "RIPE-NCC-END-MNT", "HU-NIC-MNT", "AS5507-MNT" ],
    "date_created" : "2005-06-14",
    "date_updated" : "2026-06-22",
    "source" : "RIPE"
  } ],
  "organization" : {
    "handle" : "ORG-MIST1-RIPE",
    "name" : "Magyarorszagi Internet Szolgaltatok Tanacsa Tudomanyos Egyesulet",
    "type" : "LIR",
    "address" : [ "Blathy Otto utca 9.", "1089", "Budapest", "HUNGARY" ],
    "street" : "Blathy Otto Utca",
    "city" : "Budapest",
    "zip_code" : "1089",
    "country" : [ "HU" ],
    "phone" : [ "+36 30 626 6745" ],
    "admin_contacts" : [ "ANGE11-RIPE" ],
    "tech_contacts" : [ "ANGE11-RIPE" ],
    "abuse_contacts" : [ "AR56674-RIPE" ],
    "mnt_ref" : [ "AS5507-MNT" ],
    "mnt_by" : [ "RIPE-NCC-HM-MNT", "AS5507-MNT" ],
    "date_created" : "2019-11-12",
    "date_updated" : "2026-06-22",
    "source" : "RIPE",
    "addressCountry" : "HUNGARY"
  },
  "administrative_contacts" : [ {
    "handle" : "JZ1170-RIPE",
    "name" : "Janos Zsako",
    "address" : [ "ISZT Nonprofit Kft.", "Blathy Otto u. 9.", "1089 Budapest", "Hungary" ],
    "street" : "Blathy Otto U.",
    "city" : "Budapest",
    "zip_code" : "1089",
    "country" : "HUNGARY",
    "phone" : [ "+36 1 238 0115" ],
    "mnt_by" : [ "ISZT-MNT" ],
    "date_created" : "2012-04-03",
    "date_updated" : "2026-04-10",
    "source" : "RIPE",
    "addressCountry" : "HUNGARY"
  } ],
  "technical_contacts" : [ {
    "handle" : "JZ1170-RIPE",
    "name" : "Janos Zsako",
    "address" : [ "ISZT Nonprofit Kft.", "Blathy Otto u. 9.", "1089 Budapest", "Hungary" ],
    "street" : "Blathy Otto U.",
    "city" : "Budapest",
    "zip_code" : "1089",
    "country" : "HUNGARY",
    "phone" : [ "+36 1 238 0115" ],
    "mnt_by" : [ "ISZT-MNT" ],
    "date_created" : "2012-04-03",
    "date_updated" : "2026-04-10",
    "source" : "RIPE",
    "addressCountry" : "HUNGARY"
  } ]
}

Peers

AS Number	Description	Country
AS21215	UNITED GROUP NETWORK INFRASTRUCTURE d.o.o. Beograd	RS
AS29278	Rackhost Zrt.	HU
AS42909	Community DNS Limited	GB
AS25152	Reseaux IP Europeens Network Coordination Centre RIPE NCC	NL
AS40994	Hohl IT e.U.	AT
AS5507	Magyarorszagi Internet Szolgaltatok Tanacsa Tudomanyos Egyesulet	HU
AS6939	Hurricane Electric LLC	US
AS33891	Core-Backbone GmbH	DE
AS62214	Rackforest Zrt.	HU
AS32590	Valve Corporation	US
AS6663	Euroweb Romania S.R.L.	RO
AS33891	Core Backbone GmbH	DE
AS8447	A1 Telekom Austria AG	AT
AS57344	Telehouse EAD	BG
AS1921	ipcom GmbH	AT
AS16276	OVH SAS	FR
AS15958	CETIN Ltd. Belgrade	RS
AS47692	Nessus GmbH	AT
AS49544	i3D.net B.V	NL

Upstreams

AS Number	Description	Country
AS21215	UNITED GROUP NETWORK INFRASTRUCTURE d.o.o. Beograd	RS
AS62214	Rackforest Zrt.	HU
AS15958	CETIN Ltd. Belgrade	RS
AS6939	Hurricane Electric LLC	US
AS47692	Nessus GmbH	AT
AS6663	Euroweb Romania S.R.L.	RO
AS33891	Core Backbone GmbH	DE