BGP Looking Glass
Access public BGP views from different providers to understand how your prefixes are announced and routed.
A BGP Looking Glass is a web-based tool that allows you to view BGP routing information from the perspective of different autonomous systems (ASes) around the world. It helps network administrators and engineers understand how their IP prefixes are being announced, which paths packets take, and whether routing issues exist from various global vantage points.
What is a BGP Looking Glass?
A BGP Looking Glass is a diagnostic tool that provides a window into the BGP routing tables of a specific router or autonomous system. It allows you to query real-time routing information, including prefix announcements, AS paths, and next-hop information from the perspective of that network. This is essential for troubleshooting routing issues, verifying prefix propagation, and understanding how different networks see your routes.
How does BGP Looking Glass work?
BGP Looking Glass tools connect to routers running BGP protocol and allow users to execute read-only commands such as 'show ip bgp' or 'show route'. When you query a prefix, the looking glass retrieves the routing information from that specific router's BGP table, showing you exactly how that network perceives your IP space. This provides a different perspective than using your own routers, especially when diagnosing routing problems across the global internet.
Why should I use multiple BGP Looking Glasses?
Using multiple BGP Looking Glasses from different providers is crucial because BGP routing is not always consistent across the entire internet. Different ISPs and autonomous systems may have different routing policies, peering relationships, and views of the global routing table. By checking your prefixes from several looking glasses around the world, you can verify global propagation, detect routing asymmetry, identify blackholing or filtering issues, and diagnose problems specific to certain geographic regions or network providers.
- Arelion (AS1299)
- NTT (AS2914)
- Hurricane Electric (AS6939)
- Lumen (AS209)
- Cogent (AS174)
- SWITCH (AS559)
- Init7 AG (AS13030)
- Sunrise (AS6730)
- CERN (AS513)
- DFN/WIN (AS680)
- Telus (AS852)
- BT Global Services (AS5400)
- TDC (AS3292)
- Internode (AS4739)
- Sakura Internet (AS9370)
- Neotelecoms/Eunetworks (AS8218)
- Powertel (AS9837)
- Business Internet Trends (AS12859)
- RHnet - Iceland University Research Network (AS15474)