BGP Prefix Lookup
Enter a prefix (or a single address). Answered from our daily copy of the global routing table.
240e:3b8:d000::/37
Announced exactly
- 240e:3b8:d000::/37AS134772CHINANET Guangdong province Dongguan MAN networkRPKI Valid240e:3b8:d000::
- Registry
- APNIC · China · Dec 14, 2011
- Delegated block
- 240e:200:: – 240e:3ff:ffff:ffff:ffff:ffff:ffff:ffff
Covering routes
- 240e:3b0::/28AS4134No.31,Jin-rong StreetRPKI Valid240e:3b0::
- 240e::/20AS4134No.31,Jin-rong StreetRPKI Not found240e::
More-specific routes
No more-specific routes.
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.