BGP Prefix Lookup
Enter a prefix (or a single address). Answered from our daily copy of the global routing table.
204.132.0.0/15
Announced exactly
- 204.132.0.0/15AS209CenturyLink Communications, LLCRPKI Not found204.132.0.0
- Registry
- ARIN · United States · Aug 26, 1994
- Delegated block
- 204.132.0.0 – 204.133.255.255
Covering routes
No less-specific route covers it.
More-specific routes
- 204.132.32.0/20AS393869COLORADO MOUNTAIN COLLEGERPKI Valid204.132.32.0
- 204.132.64.0/21AS17015Western Colorado UniversityRPKI Not found204.132.64.0
- 204.132.74.0/24AS17015Western Colorado UniversityRPKI Not found204.132.74.0
- 204.132.77.0/24AS17015Western Colorado UniversityRPKI Not found204.132.77.0
- 204.132.78.0/24AS17015Western Colorado UniversityRPKI Not found204.132.78.0
- 204.132.94.0/24AS3356Level 3 Parent, LLCRPKI Not found204.132.94.0
- 204.132.112.0/24AS397672Wyoming Wireless InternetRPKI Not found204.132.112.0
- 204.132.243.0/24AS10835Visionary Communications LLCRPKI Not found204.132.243.0
- 204.133.39.0/24AS19076Weld County GovernmentRPKI Valid204.133.39.0
- 204.133.40.0/24AS19076Weld County GovernmentRPKI Not found204.133.40.0
- 204.133.41.0/24AS19076Weld County GovernmentRPKI Not found204.133.41.0
- 204.133.42.0/24AS19076Weld County GovernmentRPKI Not found204.133.42.0
- 204.133.43.0/24AS19076Weld County GovernmentRPKI Not found204.133.43.0
- 204.133.44.0/24AS19076Weld County GovernmentRPKI Not found204.133.44.0
- 204.133.45.0/24AS19076Weld County GovernmentRPKI Not found204.133.45.0
- 204.133.46.0/24AS19076Weld County GovernmentRPKI Not found204.133.46.0
- 204.133.47.0/24AS19076Weld County GovernmentRPKI Not found204.133.47.0
- 204.133.48.0/24AS19076Weld County GovernmentRPKI Not found204.133.48.0
- 204.133.49.0/24AS19076Weld County GovernmentRPKI Not found204.133.49.0
- 204.133.50.0/24AS19076Weld County GovernmentRPKI Not found204.133.50.0
- 204.133.51.0/24AS19076Weld County GovernmentRPKI Not found204.133.51.0
- 204.133.52.0/24AS19076Weld County GovernmentRPKI Not found204.133.52.0
- 204.133.53.0/24AS19076Weld County GovernmentRPKI Not found204.133.53.0
- 204.133.79.0/24AS397142City of Fort CollinsRPKI Not found204.133.79.0
- 204.133.83.0/24AS397142City of Fort CollinsRPKI Not found204.133.83.0
- 204.133.115.0/24AS10835Visionary Communications LLCRPKI Not found204.133.115.0
On the internet, routes are announced as prefixes: an autonomous system tells its neighbours via BGP that it can deliver traffic for, say, 85.240.0.0/13. This tool looks a prefix up in our daily copy of the global routing table and shows three things:
- Exact announcements: which AS originates exactly this prefix. More than one origin (a MOAS) is normal for anycast services and some multihomed networks, and suspicious otherwise.
- Covering routes: less-specific announcements that contain it. Traffic follows the most specific route, so a covering route matters if the more-specific one disappears.
- More-specifics: announcements inside it, which may belong to other networks (customers, or a hijack).
Each announced route is also checked against the RPKI: whether a ROA authorises its origin AS.
The table is the view from APNIC’s route collector. Most of the global table is the same from everywhere, but a route that is filtered before it reaches that collector will not appear.
Frequently asked questions
Why is my /24 not listed but a /16 is?
Your addresses are announced as part of the larger block, and no one announces the /24 separately. That is the normal case for most customers of a provider.
What is a more-specific hijack?
Someone announces a longer prefix inside your space. Because routers prefer the most specific route, traffic goes to them. RPKI with a strict max length makes such announcements invalid.
Can I enter a single address?
Yes. The tool then shows the most specific announced route that contains it.