Cogent Communications IP Ranges
Cogent Communications is one of the largest internet backbone and transit providers in the world, operating AS174. It carries a significant share of global internet traffic and serves data centers and enterprises.
- Provider
- Cogent Communications
- Primary ASN
- AS174
- Category
- Transit
- Headquarters
- Washington, DC, USA
- Announced IPv4 prefixes
- 4005
Known IP ranges
The blocks below are the major address allocations associated with Cogent Communications. A network of this size deaggregates heavily, so an individual route in the global routing table is usually more specific than the block shown. Prefix sets change over time — use WHOIS Lookup for the authoritative current record for any specific IP.
38.0.0.0/8
66.28.0.0/16
149.6.0.0/16
154.24.0.0/13
38.104.0.0/13
Where the current list lives
Cogent publishes an RFC 8805 geofeed, a CSV that maps its prefixes to locations, and declares it in its ARIN registry record: 98,071 lines when read on 21 Oct 2026. geofeed.cogentco.com/geofeed.csv
The current view of what the network announces is in the routing table: AS174 on RIPEstat.
What does a Cogent Communications IP mean in a privacy test?
A Cogent IP (AS174) usually appears as a transit hop in a traceroute rather than as an exit IP. If you see AS174 as your visible address, you may be behind a data center or hosting service that buys transit from Cogent.
Related tools
Frequently asked questions
What IP ranges does Cogent use?
Cogent operates the large 38.0.0.0/8 block plus ranges such as 66.28.0.0/16 and 149.6.0.0/16 under AS174. Cogent also announces routes for its transit customers.
Why does Cogent appear in my traceroute?
Cogent is one of the largest global transit providers. Internet traffic frequently crosses Cogent backbone routers between networks. Seeing AS174 in a traceroute is normal.
Is a Cogent IP a VPN or data center address?
Cogent sells internet access to businesses, carriers and content providers, plus colocation in its 88 data centres. An IP announced by AS174 is usually a business or server connection, not a home line.
How do I look up a Cogent IP address?
Use MyIPScan IP Geolocation Lookup. IPs that Cogent routes itself return AS174 (Cogent Communications); many addresses inside Cogent's 38.0.0.0/8 and 154.24.0.0/13 are announced by other networks and return their ASN instead.
What ASN does Cogent use?
Cogent uses AS174 as its primary transit ASN. Use ASN Lookup to see what AS174 announces today.