BGP Prefix Lookup
Enter a prefix (or a single address). Answered from our daily copy of the global routing table.
203.168.0.0/19
Announced exactly
- 203.168.0.0/19AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.0.0
- Registry
- APNIC · China · Apr 12, 2011
- Delegated block
- 203.168.0.0 – 203.168.31.255
Covering routes
No less-specific route covers it.
More-specific routes
- 203.168.0.0/23AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.0.0
- 203.168.2.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.2.0
- 203.168.3.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.3.0
- 203.168.5.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.5.0
- 203.168.6.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.6.0
- 203.168.7.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.7.0
- 203.168.8.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.8.0
- 203.168.9.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.9.0
- 203.168.10.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.10.0
- 203.168.11.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.11.0
- 203.168.12.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.12.0
- 203.168.13.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.13.0
- 203.168.14.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.14.0
- 203.168.15.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.15.0
- 203.168.16.0/23AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.16.0
- 203.168.18.0/24AS137692IOT Guangdong network, Chinatelecom, P.R.China.RPKI Valid203.168.18.0
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.