asn.dev

Observed topology

AS137 ASGARR Consortium GARR

Upstreams 13 carry this network
Downstreams 13 this network carries
Adjacent (IPv4) 24
Adjacent (IPv6) 14

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS137: the AS immediately before it in a routing path. Ranked by how many paths showed the relationship, which reflects how widely it is used, not how much traffic crosses it.

ASNetworkTypeFamiliesPaths seen
AS174Cogent Communications, LLCTransitIPv4 IPv62,129
AS6762TELECOM ITALIA SPARKLE S.p.A.TransitIPv4 IPv61,487
AS6461Zayo BandwidthTransitIPv4 IPv6575
AS20965GEANT VerenigingUnclassifiedIPv4 IPv6500
AS3303Swisscom (Schweiz) AGResidentialIPv4 IPv6166
AS21320GEANT VerenigingUnclassifiedIPv4 IPv687
AS24482SG.GSHostingIPv4 IPv684
AS31543myNet GmbHResidentialIPv4 IPv683
AS59919Brainbox S.r.l.ResidentialIPv482
AS57463NetIX Communications JSCUnclassifiedIPv482
AS29632Netassist International EOODUnclassifiedIPv64
AS13030Init7 (Switzerland) Ltd.HostingIPv62
AS12779IT.Gate S.p.A.UnclassifiedIPv41

Inferred from path position, not from any declaration by either party. A network appearing here is carrying these routes; whether that is a paid transit arrangement, a backup, or something else is not something routing data can tell you.

Transit

Downstream networks

inferred

Networks for which AS137 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS31638Lepida S.c.p.A.UnclassifiedIPv42,968
AS42081European Centre for Medium-Range Weather Forecasts (ECMWF)UnclassifiedIPv4 IPv6430
AS2597Consiglio Nazionale delle RicercheUnclassifiedIPv4 IPv689
AS5502SACLANT Undersea Research CentreUnclassifiedIPv464
AS20745CNIT Italian National Consortium for TelecommunicationsUnclassifiedIPv464
AS200375Istituto Nazionale di Geofisica e VulcanologiaUnclassifiedIPv464
AS42165Directorate General - Joint Research CentreUnclassifiedIPv464
AS16004Milan Internet eXchangeUnclassifiedIPv4 IPv615
AS35110Regione BasilicataUnclassifiedIPv414
AS12New York UniversityUnclassifiedIPv412
AS8978Vatican City StateUnclassifiedIPv4 IPv611
AS199342Universita Cattolica del Sacro CuoreUnclassifiedIPv48
AS49976AREA SCIENCE PARKUnclassifiedIPv48

Adjacency

Adjacent networks

38 shown

Every AS seen directly next to AS137 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS174Cogent Communications, LLCTransitIPv4 IPv63,662
AS31638Lepida S.c.p.A.UnclassifiedIPv42,968
AS6762TELECOM ITALIA SPARKLE S.p.A.TransitIPv4 IPv62,550
AS6461Zayo BandwidthTransitIPv4 IPv6984
AS20965GEANT VerenigingUnclassifiedIPv4 IPv6937
AS42081European Centre for Medium-Range Weather Forecasts (ECMWF)UnclassifiedIPv4 IPv6430
AS3303Swisscom (Schweiz) AGResidentialIPv4 IPv6294
AS2597Consiglio Nazionale delle RicercheUnclassifiedIPv4 IPv6193
AS24482SG.GSHostingIPv4 IPv6156
AS21320GEANT VerenigingUnclassifiedIPv4 IPv6154
AS59919Brainbox S.r.l.ResidentialIPv4149
AS57463NetIX Communications JSCUnclassifiedIPv4149
AS31543myNet GmbHResidentialIPv4 IPv6145
AS20745CNIT Italian National Consortium for TelecommunicationsUnclassifiedIPv464
AS200375Istituto Nazionale di Geofisica e VulcanologiaUnclassifiedIPv464
AS42165Directorate General - Joint Research CentreUnclassifiedIPv464
AS5502SACLANT Undersea Research CentreUnclassifiedIPv464
AS8978Vatican City StateUnclassifiedIPv4 IPv619
AS29632Netassist International EOODUnclassifiedIPv616
AS16004Milan Internet eXchangeUnclassifiedIPv4 IPv615
AS35110Regione BasilicataUnclassifiedIPv414
AS12New York UniversityUnclassifiedIPv412
AS49976AREA SCIENCE PARKUnclassifiedIPv48
AS13030Init7 (Switzerland) Ltd.HostingIPv68
AS199342Universita Cattolica del Sacro CuoreUnclassifiedIPv48
AS12779IT.Gate S.p.A.UnclassifiedIPv41

Adjacency is not the same as peering. Being next to each other in a path covers paid transit, settlement-free peering and customer connections alike, and routing data cannot distinguish them. Treat this as "these networks exchange routes", nothing more specific.

Interconnection

Exchange presence

recorded

Internet exchanges where Packet Clearing House has a port recorded for AS137, largest fabric first. An exchange is shared switching where networks interconnect directly rather than paying a transit provider to carry traffic between them, so turning up at one is a deliberate choice about how this network wants to be reached. Each name opens that exchange's own page, with its peering LANs and every other network recorded on it. Recorded at 3 exchanges across 1 country and 1 region.

ExchangeLocationTheir addressMember ports
Milan Internet ExchangeMilan, Italy217.29.66.39416
Roma Internet Exchange PointRome, Italy193.201.28.15225
Torino Piemonte Exchange PointTorino, Italy194.116.96.25123

Unlike the tables above, this is recorded rather than inferred. An address on a peering LAN is at that exchange by definition. Two carve-outs all the same. Member ports counts every participant at the exchange, not this network's ports, so read it as a size proxy. And an absent exchange means PCH has no record of it, not that the network is not there.

Provenance

Where this comes from

Derived from routing tables collected at 2026-08-08 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 74.02M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.

Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.

Exchange presence comes from a separate dataset: the directory collected 2026-08-09 by Packet Clearing House (https://www.pch.net/ixp/data), covering 1,327 exchanges and 93,164 recorded member ports, licensed CC BY-NC-SA 3.0.

PeeringDB is the better-known directory and is deliberately not the source here: its acceptable-use policy forbids the bulk storage this needs. The two answer different questions anyway. PeeringDB reports what an operator declares about itself; this reports what PCH has recorded.