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AS397285Cambridge Telephone

United StatesRegistryARIN

As of 26th September 2026, AS397285 (Cambridge Telephone), a network registered in the United States with ARIN, originates 5 IPv4 prefixes covering 2.8k addresses. By IPv4 address space that makes it the 22,343rd-largest of the 79,516 networks we see originating IPv4, and the 5,682nd-largest of 18,424 in the United States. It is seen behind 1 upstream network, most often AS15305 (Syringa Networks, LLC), 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

5

IPv6 prefixes

0

IPv4 addresses

2.8k

IPv6 /64s

0

Upstream graph

The networks AS397285 is seen behind, one and two hops out, drawn from real AS paths.

AS397285Toward the internet core
Upstream graph for AS397285: 3 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS397285Cambridge Telepho…This networkAS15305Syringa Networks,…AS209Lumen (ex. Qwest)AS1299Arelion (fka. Tel…

Networks observed one and two hops upstream of AS397285 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

4

adjacent networks

Upstreams
125%
Peers
250%
Downstreams
125%

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

Upstreams of AS397285
NetworkCountryRelationshipPathsVantage pts
AS15305Syringa Networks, LLCUSPeer64881

Prefixes

The largest blocks AS397285 originates, widest first.

Largest prefixes originated by AS397285
PrefixAddressesVisibility
45.33.208.0/221k81/81
45.33.212.0/221k81/81
45.33.216.0/2425681/81
45.33.220.0/2425681/81
45.33.223.0/2425681/81

Routing health

How AS397285'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%5
  • Invalid0.0%0
  • No ROA0.0%0

Propagation

  • Globally propagated90% of full-feed peers or more100.0%5
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 5 prefixes

Recent changes

Announcements that started or stopped since 28th Aug 2026.

No announcement by AS397285 started or stopped in this period.

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