asn.dev

Autonomous system

AS51257 CERIZ

Unclassified ARIN

IPv4 addresses 256 1 prefixes
IPv6 prefixes 20 counted as prefixes, not addresses
Countries 1 mostly FR
Exchanges 0 recorded by PCH
Upstreams 1 0 downstream
Flagged prefixes 0 none

Summary

CERIZ

France · AI-generated

business enterprise regional

The AS handle CERIZ is held by CERIZ SASU.

What it's used for

  • The address space carries enterprise traffic, identified by the netname FR-CERIZ-20190131 and registrant CERIZ SASU.
  • The network announces 256 IPv4 addresses and 20 IPv6 prefixes, with a single observed neighbour, indicating a small-scale internal corporate estate rather than a transit or access provider.
  • Traffic from this AS consists of office workers and internal business endpoints for the CERIZ organization.

Notable

  • The registrant CERIZ SASU agrees with the announcer, confirming a direct ownership relationship.
  • The address inventory is compact, consisting of a single IPv4 /24 block and a set of IPv6 prefixes under the 2a05:d80::/34 range.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.

Interconnection

Peering at a glance

Full topology · Graph

Internet exchanges

No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.

Transit providers

1 upstream, 0 downstream and 2 adjacent networks observed; most-used upstreams first.

ASNetworkPaths seen
AS29075IELO-LIAZO SERVICES SAS130

Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-13, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.

Address space

Summary

Shape and geography

IPv4 1 prefixes · 256 addresses IPv6 20 prefixes

CountryNamePrefixes
FRFrance21

Registry

Allocation record

ARIN · via Atlas (registry + RDAP)
Registry
ARIN
Handle
AS51257
Registry name
CERIZ
Registrant
MNT-CERIZ
Abuse contact
jerome@fair-telecom.fr
Registered
2016-01-05
Last changed
2024-01-27
Allocation
allocated

Routing security

RPKI and IRR

Full detail
RPKI
100% valid · 3 valid, 0 with no ROA
ROAs
3 authorising AS51257
ASPA
no ASPA record
IRR
100% registered · 3 of 3 announcements
Route objects
2 naming AS51257

Reputation

Classification and threat

Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.

Spamhaus DROP

Not on ASN-DROP The network as a whole is not listed.

No DROP prefixes None of its announced space is on the DROP prefix list.

Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 442 networks and 1,773 prefixes, as published 2026-10-13. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.

FBI IC3

No IC3 indicators Nothing from the FBI IC3 feed.

IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.

Elsewhere

Cross-check