% APNIC found the following authoritative answer from: whois.ripe.net

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

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

% Information related to '131.224.0.0 - 131.224.255.255'

% Abuse contact for '131.224.0.0 - 131.224.255.255' is 'cert@surfcert.nl'

inetnum:        131.224.0.0 - 131.224.255.255
netname:        RIVMNET
country:        NL
remarks:        For general abuse like spam use the address
remarks:        Peter.Berndsen@rivm.nl
remarks:        For security related contacts use the address
remarks:        cert@SURFnet.nl
org:            ORG-RVVE1-RIPE
status:         LEGACY
admin-c:        PB2064-RIPE
tech-c:         NB1136-RIPE
mnt-by:         RIPE-NCC-LEGACY-MNT
mnt-by:         SN-LIR-MNT
mnt-irt:        irt-SURFcert
created:        1970-01-01T00:00:00Z
last-modified:  2020-11-16T17:42:47Z
source:         RIPE
sponsoring-org: ORG-Sb3-RIPE

organisation:   ORG-RVVE1-RIPE
org-name:       Rijksinstituut voor Volksgezondheid en Milieuhygiene
country:        NL
org-type:       OTHER
address:        P.O. Box 1
address:        NL-3720 BA Bilthoven
address:        The Netherlands
phone:          +31 30 2742456
admin-c:        PB2064-RIPE
tech-c:         NB1136-RIPE
mnt-by:         SN-LIR-MNT
mnt-ref:        SN-LIR-MNT
abuse-c:        SNS1-RIPE
created:        2015-05-07T09:58:40Z
last-modified:  2022-12-01T17:31:36Z
source:         RIPE # Filtered

person:         Nico Blokhuijzen
address:        Rijksinstituut voor Volksgezondheid en Milieuhygiene
address:        P.O. Box 1
address:        NL-3720 BA Bilthoven
address:        The Netherlands
phone:          +31 30 2742456
nic-hdl:        NB1136-RIPE
created:        1970-01-01T00:00:00Z
last-modified:  2016-04-05T17:54:16Z
mnt-by:         RIPE-NCC-LOCKED-MNT
source:         RIPE # Filtered

person:         Peter Berndsen
address:        Rijksinstituut voor Volksgezondheid en Milieuhygiene
address:        P.O. Box 1
address:        NL-3720 BA Bilthoven
phone:          +31 30 2742961
fax-no:         +31 30 2742971
nic-hdl:        PB2064-RIPE
created:        1970-01-01T00:00:00Z
last-modified:  2020-06-04T12:33:46Z
source:         RIPE # Filtered
mnt-by:         SN-LIR-MNT

% Information related to '131.224.0.0/16AS1103'

route:          131.224.0.0/16
descr:          RIVMNET
origin:         AS1103
mnt-by:         AS1103-MNT
created:        2002-03-21T15:59:37Z
last-modified:  2002-03-21T15:59:37Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.112 (DEXTER)

Search for
IP address lookups			Miscellaneous queries
-l	1st level less specific		-i	Inverse attributes	None admin-c admin-c,tech-c,zone-c author cross-mnt cross-nfy local-as mbrs-by-ref member-of mnt-by mnt-lower mnt-nfy mnt-routes notify nserver origin person referral-by rev-srv sub-dom tech-c upd-to zone-c
-L	All less specific		-T	Object types	All as-block as-set aut-num domain filter-set inet-rtr inet6num inetnum irt key-cert mntner peering-set person role route route-set rtr-set
-m	1st level more specific
-M	All more specific		Query hints Include "AS" in front of an AS number. Example: AS4808 Include "-t" (template only) or "-v" (template and description) in front of an object name to view the template Example: -t inetnum
-x	Exact match only
-d	Associated reverse domain