subnet.im

AS51906recast IT GmbH & Co. KG

GermanyRegistryRIPE NCC

As of 10th November 2026, AS51906 (recast IT GmbH & Co. KG), a network registered in Germany with RIPE NCC, originates 13 IPv4 prefixes covering 23.3k addresses and 3 IPv6 prefixes. By IPv4 address space that makes it the 6,583rd-largest of the 80,723 networks we see originating IPv4, and the 235th-largest of 2,329 in Germany. It is seen behind 6 upstream networks, most often AS13237 (euNetworks GmbH) and AS3356 (Lumen (Level 3)), and in front of 1 downstream network. Every one of its announcements has a valid RPKI ROA, and none are RPKI-invalid. 100% of its routes reach at least 90% of full-feed peers.

At a glance

IPv4 prefixes

13

IPv6 prefixes

3

IPv4 addresses

23.3k

IPv6 /64s

4.3B

Upstream graph

The networks AS51906 is seen behind, one and two hops out, drawn from real AS paths.

AS51906Toward the internet core
Upstream graph for AS51906: 11 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS51906recast IT GmbH & …This networkAS3223Voxility LLPAS3356Lumen (Level 3)AS6939Hurricane Electri…AS13237euNetworks GmbHAS24961WIIT AG (fka. myL…AS2914NTT America, Inc.AS3549Lumen (fka. Globa…AS20130Depaul UniversityAS132337AxclusiveAS1299Arelion (fka. Tel…AS3257GTT Communication…

Networks observed one and two hops upstream of AS51906 in real AS paths. A thicker line means more vantage points saw that adjacency, so weight tracks how well attested it is — not how much traffic it carries. Adjacency is an observation; whether it is a transit purchase or a settlement-free peering is an inference, and is labelled as one wherever we show it.

Neighbouring networks

21

adjacent networks

Upstreams
629%
Peers
1467%
Downstreams
15%

Networks carrying this one's traffic toward the rest of the internet.

Upstreams of AS51906
NetworkCountryRelationshipPathsVantage pts
AS13237euNetworks GmbHDEPeer480118
AS3356Lumen (Level 3)USPeer39851
AS3223Voxility LLPGBPeer30476
AS24961WIIT AG (fka. myLoc Managed IT AG)DEPeer14622
AS6939Hurricane Electric LLCUSPeer12954
AS24482SG.GSSGPeer91

Prefixes

The largest blocks AS51906 originates, widest first.

Largest prefixes originated by AS51906
PrefixAddressesVisibility
31.204.112.0/204.1k76/76
37.130.128.0/204.1k76/76
91.106.0.0/204.1k76/76
176.241.160.0/204.1k76/76
79.171.56.0/212k76/76
146.66.224.0/212k76/76
91.106.0.0/221k76/76
82.197.132.0/2351276/76
31.204.115.0/2425676/76
37.130.139.0/2425676/76

Routing health

How AS51906's own announcements validate against RPKI and how far they propagate. The same measures for the whole routing table are on the routing table in numbers.

RPKI origin validation

  • Valid100.0%16
  • Invalid0.0%0
  • No ROA0.0%0

Propagation

  • Globally propagated90% of full-feed peers or more100.0%16
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 13 prefixes

IPv6 — 3 prefixes

  • /324.3B × /6433.3%1
  • /3933.6M × /6433.3%1
  • /4865.5k × /6433.3%1

Recent changes

Announcements that started or stopped since 11th Oct 2026.

No announcement by AS51906 started or stopped in this period.

Routing data derived from RouteViews MRT archives, BGPKIT relationship inference and public registry data.