asn.dev

Observed topology

AS43205 BULSATCOM-BG-AS Sofia

Upstreams 17 carry this network
Downstreams 1 this network carries
Adjacent (IPv4) 17
Adjacent (IPv6) 3

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS43205: 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
AS8866Vivacom Bulgaria EADResidentialIPv462
AS3356Level 3 Parent, LLCTransitIPv4 IPv636
AS9002RETN LimitedUnclassifiedIPv4 IPv635
AS6939Hurricane Electric LLCTransitIPv47
AS21215UNITED GROUP NETWORK INFRASTRUCTURE d.o.o. BeogradResidentialIPv64
AS34549meerfarbig GmbH & Co. KGHostingIPv44
AS33891Core-Backbone GmbHHostingIPv42
AS20485Joint Stock Company TransTeleComUnclassifiedIPv41
AS48362Stadtwerke FeldkirchResidentialIPv41
AS57463NetIX Communications JSCUnclassifiedIPv41
AS12552GlobalConnect ABUnclassifiedIPv41
AS37721Virtual Technologies & SolutionsResidentialIPv41
AS37100SEACOM LimitedUnclassifiedIPv41
AS212024Marc SchmittUnclassifiedIPv41
AS34019Hivane AssociationUnclassifiedIPv41
AS17639Converge ICT Solutions Inc.UnclassifiedIPv41
AS24482SG.GSHostingIPv41

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 AS43205 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS209681Deltacom Electronics Ltd.UnclassifiedIPv41

Adjacency

Adjacent networks

20 shown

Every AS seen directly next to AS43205 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS8866Vivacom Bulgaria EADResidentialIPv462
AS3356Level 3 Parent, LLCTransitIPv4 IPv636
AS9002RETN LimitedUnclassifiedIPv4 IPv635
AS6939Hurricane Electric LLCTransitIPv47
AS21215UNITED GROUP NETWORK INFRASTRUCTURE d.o.o. BeogradResidentialIPv64
AS34549meerfarbig GmbH & Co. KGHostingIPv44
AS57463NetIX Communications JSCUnclassifiedIPv42
AS33891Core-Backbone GmbHHostingIPv42
AS209681Deltacom Electronics Ltd.UnclassifiedIPv41
AS48362Stadtwerke FeldkirchResidentialIPv41
AS12552GlobalConnect ABUnclassifiedIPv41
AS34019Hivane AssociationUnclassifiedIPv41
AS17639Converge ICT Solutions Inc.UnclassifiedIPv41
AS37721Virtual Technologies & SolutionsResidentialIPv41
AS212024Marc SchmittUnclassifiedIPv41
AS37100SEACOM LimitedUnclassifiedIPv41
AS24482SG.GSHostingIPv41
AS20485Joint Stock Company TransTeleComUnclassifiedIPv41

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 AS43205, 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 5 exchanges across 2 countries and 1 region.

ExchangeLocationTheir addressMember ports
DE-CIX FrankfurtFrankfurt, Germany80.81.192.2481,073
NetIXSofia, Bulgaria185.1.226.146264
Bulgarian Internet eXchangeSofia, Bulgaria193.169.198.224137
Balkan Internet ExchangeSofia, Bulgaria185.1.30.3367
T-CIXSofia, Bulgaria185.1.40.2820

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.