Observed topology

AS56737 STADTWERKE-FLENSBURG-AS Stadtwerke Flensburg GmbH

Unclassified APNIC

Upstreams 4 carry this network

Downstreams 2 this network carries

Adjacent (IPv4) 6

Adjacent (IPv6) 3

Upstream graph Who carries AS56737, and who carries them, drawn as a map up to the transit-free core. 0 exchanges Where AS56737 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS56737: 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.

AS	Network	Type	Families	Paths seen
AS50629	LWLcom GmbH	Unclassified	IPv4	68
AS6797	GlobalConnect AB	Unclassified	IPv4 IPv6	40
AS8881	1&1 Versatel GmbH	Residential	IPv4 IPv6	37
AS31027	GlobalConnect A/S	Unclassified	IPv4 IPv6	10

Transit

Downstream networks

inferred

Networks for which AS56737 was observed as the last hop before the origin, meaning it appears to provide them transit.

AS	Network	Type	Families	Paths seen
AS204135	LEMARIT GmbH	Unclassified	IPv4	59
AS8956	Stadt Flensburg	Unclassified	IPv4	32

Adjacency

Adjacent networks

observed

Every AS seen directly next to AS56737 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS50629	LWLcom GmbH	Unclassified	IPv4	132
AS8881	1&1 Versatel GmbH	Residential	IPv4 IPv6	75
AS6797	GlobalConnect AB	Unclassified	IPv4 IPv6	65
AS204135	LEMARIT GmbH	Unclassified	IPv4	59
AS31027	GlobalConnect A/S	Unclassified	IPv4 IPv6	38
AS8956	Stadt Flensburg	Unclassified	IPv4	32

Provenance

Where this comes from

Derived from routing tables collected at 2026-11-14 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 74.46M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.

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. 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.

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