AS174Cogent Communications, LLC

United StatesRegistryARINTypeT1

As of 26th September 2026, AS174 (Cogent Communications, LLC), a tier-1 transit network registered in the United States with ARIN, originates 3,983 IPv4 prefixes covering 37.6M addresses and 528 IPv6 prefixes. By IPv4 address space that makes it the 16th-largest of the 79,480 networks we see originating IPv4, and the 10th-largest of 18,421 in the United States. It is seen behind 134 upstream networks, most often AS151326 (DCConnect Communication Pte. Ltd.) and AS1299 (Arelion (fka. Telia Carrier)), and in front of 6,374 downstream networks. 10% of its announcements have a valid RPKI ROA; 20 are RPKI-invalid. 49% of its routes reach at least 90% of full-feed peers, and 190 prefixes are also originated by another network.

At a glance

IPv4 prefixes

3,983

IPv6 prefixes

528

IPv4 addresses

37.6M

IPv6 /64s

250B

Upstream graph

The networks AS174 is seen behind, one and two hops out, drawn from real AS paths.

AS174Toward the internet core

Networks observed one and two hops upstream of AS174 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

13,120

adjacent networks

Upstreams: 1341%
Peers: 6,61250%
Downstreams: 6,37449%

Networks carrying this one's traffic toward the rest of the internet. Listing the 40 seen on the most AS paths, of 134.

Upstreams of AS174
Network	Country	Relationship	Paths	Vantage pts
AS151326DCConnect Communication Pte. Ltd.	SG	Peer	750,381	1
AS1299Arelion (fka. Telia Carrier)	SE	Peer	702,912	82
AS6453TATA Communications (America) Inc	US	Peer	659,167	63
AS3491PCCW Global (HK) Ltd.	HK	Peer	518,391	17
AS3130RGnet OU	EE	Peer	479,905	1
AS7713PT Telkom Indonesia Tbk	ID	Peer	437,733	11
AS3356Lumen (Level 3)	US	Peer	428,179	96
AS2497Internet Initiative Japan Inc.	JP	Peer	344,346	6
AS3170VeloxServ Communications Ltd	GB	Peer	337,476	2
AS32590Valve Corporation	US	Peer	333,681	2

Prefixes

All 4,511

The largest blocks AS174 originates, widest first.

Largest prefixes originated by AS174
Prefix	Addresses	Visibility
0.0.0.0/0	4.3B	1/81
38.0.0.0/8	16.8M	79/81
208.0.0.0/11	2.1M	79/81
63.160.0.0/12	1M	79/81
154.48.0.0/12	1M	79/81
65.160.0.0/13	524k	79/81
154.24.0.0/13	524k	79/81
154.40.0.0/13	524k	79/81
205.240.0.0/13	524k	79/81
65.168.0.0/14	262k	80/81

Routing health

How AS174'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

Valid10.4%467
Invalid0.4%20
No ROA89.2%4,024

Propagation

Globally propagated90% of full-feed peers or more48.7%2,197
Partially propagated40% to 90%2.6%118
Seen by few peersUnder 40%48.7%2,196

Prefix sizes

IPv4 — 3,983 prefixes

IPv6 — 528 prefixes

/2868.7B × /640.2%1
/2934.4B × /640.6%3
/324.3B × /643.2%17
/332.1B × /640.4%2
/36268M × /640.8%4
/424.2M × /640.2%1
/441M × /640.6%3
/4865.5k × /6479.2%418
/49 and longerAggregated15.0%79

Recent changes

Announcements that started or stopped since 27th Aug 2026.

Announced38.84.28.0/2425th Sept 2026
Announced38.84.29.0/2425th Sept 2026
Announced38.84.30.0/2425th Sept 2026
Announced38.84.31.0/2425th Sept 2026
Withdrawn82.129.27.0/2425th Sept 2026
Withdrawn192.166.139.0/2425th Sept 2026
Withdrawn82.152.113.0/2425th Sept 2026
Withdrawn199.48.182.0/2425th Sept 2026
Announced185.239.172.0/2424th Sept 2026
Announced149.115.108.0/2424th Sept 2026
Withdrawn149.115.108.0/2424th Sept 2026
Withdrawn149.6.125.0/2424th Sept 2026

424 announced and 302 withdrawn in all; the most recent are shown.

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