BGP Prefix Lookup
Enter a prefix (or a single address). Answered from our daily copy of the global routing table.
42.80.0.0/15
Announced exactly
- 42.80.0.0/15AS17638ASN for TIANJIN Provincial Net of CTRPKI Not found42.80.0.0
- Registry
- APNIC · China · Feb 21, 2011
- Delegated block
- 42.80.0.0 – 42.81.255.255
Covering routes
No less-specific route covers it.
More-specific routes
- 42.80.20.0/23AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.20.0
- 42.80.30.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.30.0
- 42.80.31.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.31.0
- 42.80.33.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.33.0
- 42.80.41.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.41.0
- 42.80.42.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.42.0
- 42.80.43.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.43.0
- 42.80.216.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.216.0
- 42.80.218.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.218.0
- 42.80.219.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.219.0
- 42.80.239.0/24AS17638ASN for TIANJIN Provincial Net of CTRPKI Valid42.80.239.0
- 42.81.0.0/16AS58542Tianjij,300000RPKI Valid42.81.0.0
- 42.81.60.0/24AS58542Tianjij,300000RPKI Invalid42.81.60.0
- 42.81.138.0/24AS58542Tianjij,300000RPKI Valid42.81.138.0
- 42.81.168.0/24AS58542Tianjij,300000RPKI Valid42.81.168.0
- 42.81.169.0/24AS58542Tianjij,300000RPKI Valid42.81.169.0
- 42.81.170.0/24AS58542Tianjij,300000RPKI Valid42.81.170.0
- 42.81.171.0/24AS58542Tianjij,300000RPKI Valid42.81.171.0
- 42.81.172.0/24AS58542Tianjij,300000RPKI Valid42.81.172.0
- 42.81.173.0/24AS58542Tianjij,300000RPKI Valid42.81.173.0
On the internet, routes are announced as prefixes: an autonomous system tells its neighbours via BGP that it can deliver traffic for, say, 49.224.0.0/14. 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.