Understanding BGP Looking Glass Servers

Understanding BGP Looking Glass Servers

Amidst this complex network ecosystem, BGP Looking Glass servers stand as invaluable tools offering transparency and insight into the world of routing. They are used to troubleshoot and visualize how networks view routes. BGP Looking Glass servers are essentially web-based tools or servers provided by network service providers, internet exchanges, or organizations. They enable users, including network administrators, researchers, and curious enthusiasts, to interact with routers remotely and gather real-time information about BGP routing tables and network connectivity.

Functionality and Features

  1. Routing Information Retrieval: Looking Glass servers allow users to query routers across various networks, retrieving routing information, such as BGP routing tables, advertised routes, and paths to specific IP addresses or prefixes. Knowing how multiple networks view their paths to get to your network helps diagnose issues. Many network administrators forget that the view of your routes from inside your ASN differs from how external networks on the Internet view those routes.
  2. Troubleshooting and Diagnosis: These servers serve as a troubleshooting aid by providing insights into network issues, including route flaps, route changes, and inconsistencies in advertised routes between networks.
  3. Route Visualization and Validation: Users can validate the propagation of routes and visualize the path taken by packets across different network hops, aiding in understanding network topology and diagnosing routing problems.
  4. BGP Peer Analysis: Looking Glass servers enable users to analyze BGP peering sessions between routers, check the status of BGP neighbors, and examine BGP attributes exchanged between peers.

How Looking Glass Servers Benefit Networking

  1. Transparency and Visibility: Looking Glass servers offer a transparent view of BGP routing information across different networks, providing visibility into how routes are propagated and ensuring adherence to best practices.
  2. Troubleshooting and Debugging: Network administrators utilize Looking Glass servers to diagnose and debug routing issues, verify routing policies, and resolve network connectivity problems.
  3. Routing Policy Verification: These servers aid in verifying routing policies and configurations by allowing users to observe how their routes are propagated and interpreted by different BGP-speaking routers.
  4. Research and Analysis: Researchers and analysts leverage Looking Glass servers to conduct studies, analyze global routing behavior, and gain insights into the structure and dynamics of the internet.

Accessing Looking Glass Servers

Various network service providers and internet exchanges offer public or restricted access to their Looking Glass servers via web interfaces or command-line tools. Users can access these servers to query specific routers or networks and retrieve relevant routing information.

Some of my favorites are:

https://lg.he.net/ – Hurricane Electric has an extensive library of BGP tools, found at https://bgp.he.net/ .

https://www.cogentco.com/en/looking-glass – Cogent Looking Glass

https://www.verizon.com/business/why-verizon/looking-glass/ – Verizon Looking Glass

https://lg.telia.net/ – telia Looking Glass

j2networks family of sites
#packetsdownrange #routethelight