subnet.im

AS33667Comcast Cable Communications, LLC

United StatesRegistryARIN

As of 11th November 2026, AS33667 (Comcast Cable Communications, LLC), a network registered in the United States with ARIN, originates 69 IPv4 prefixes covering 70.1k addresses and 57 IPv6 prefixes. By IPv4 address space that makes it the 3,158th-largest of the 80,747 networks we see originating IPv4, and the 1,038th-largest of 18,752 in the United States. It is seen behind 2 upstream networks, most often AS7922 (Comcast Cable Communications, LLC) and AS3356 (Lumen (Level 3)), and in front of 142 downstream networks. 80% of its announcements have a valid RPKI ROA; 9 are RPKI-invalid. 69% of its routes reach at least 90% of full-feed peers, and 58 prefixes are also originated by another network.

At a glance

IPv4 prefixes

69

IPv6 prefixes

57

IPv4 addresses

70.1k

IPv6 /64s

34.4B

Upstream graph

The networks AS33667 is seen behind, one and two hops out, drawn from real AS paths.

AS33667Toward the internet core
Upstream graph for AS33667: 6 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS33667Comcast Cable Com…This networkAS3356Lumen (Level 3)AS7922Comcast Cable Com…AS2914NTT America, Inc.AS3549Lumen (fka. Globa…AS1299Arelion (fka. Tel…AS6453TATA Communicatio…

Networks observed one and two hops upstream of AS33667 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

292

adjacent networks

Upstreams
21%
Peers
14851%
Downstreams
14249%

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

Upstreams of AS33667
NetworkCountryRelationshipPathsVantage pts
AS7922Comcast Cable Communications, LLCUSPeer10,413139
AS3356Lumen (Level 3)USPeer7,33053

Prefixes

All 126

The largest blocks AS33667 originates, widest first.

Largest prefixes originated by AS33667
PrefixAddressesVisibility
140.89.64.0/1816.4k29/76
9.142.96.0/198.2k73/76
135.132.64.0/198.2k72/76
9.142.48.0/204.1k73/76
138.226.64.0/204.1k73/76
23.230.200.0/212k26/76
138.226.48.0/212k72/76
138.226.112.0/212k73/76
138.226.192.0/212k1/76
135.132.72.0/221k4/76

Routing health

How AS33667'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

  • Valid80.2%101
  • Invalid7.1%9
  • No ROA12.7%16

Propagation

  • Globally propagated90% of full-feed peers or more69.0%87
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%31.0%39

Prefix sizes

IPv4 — 69 prefixes

IPv6 — 57 prefixes

  • /2934.4B × /641.8%1
  • /441M × /641.8%1
  • /4865.5k × /6496.5%55

Recent changes

Announcements that started or stopped since 12th Oct 2026.

10 announced and 8 withdrawn in all; the most recent are shown.

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