**[This is in development. Suggestions or corrections are welcome!]**
# R&E Global LPP Report
The attached HTML file is a self-contained, interactive copy of the report. Open it in any modern web browser to explore the full tree with search, sort, and expand/collapse controls.
## What this report shows
The global R&E network consists of roughly 2,700 separate networks (autonomous systems). A significant percentage of these networks have connections to both an upstream R&E provider and one or more commodity ISPs. Each network independently decides which path to prefer when routing traffic to various destinations.
Campuses typically connect to a regional R&E network (e.g., MERIT, LEARN, CENIC, NYSERNet), which in turn connects to Internet2. The R&E route between two campuses is often at least 4 AS hops. If both campuses use the same commodity ISP — which happens frequently — the commodity route might only be 2 hops. Without an explicit routing policy, BGP selects the shortest AS path, and the two campuses will route via the commodity ISP instead of the R&E network.
The recommended best practice is to use **BGP Local Preference** to prefer routes learned from R&E networks over routes learned from commodity ISPs. When this is done, campuses route via the R&E path regardless of AS-path length.
This report visualizes routing preference data for all 2,700 R&E networks, organized as an AS-path tree rooted at Internet2 (AS 11537).
## How the probe works
The Local Preference Probe (LPP) is a server connected to both the Internet2 R&E network and a commodity ISP. It sends probes from two source addresses to hosts across the R&E networks and observes how each network routes its response back — does it arrive via the R&E path or the commodity path?
| Source | Address | Route design | |--------|---------|-------------| | Source A | `163.253.64.1` | R&E route is prepended towards commodity | | Source B | `163.253.63.63` | R&E route is prepended towards R&E |
Both sources share the same commodity route. The difference is which direction the R&E route is prepended, so the two probes test whether the remote network chooses based on Local Preference or AS-path length.
## Reading the results
Each network in the tree has a stacked bar showing three categories:
| Color | Source A return | Source B return | Meaning | |-------|----------------|-----------------|---------| | **Green (RE)** | R&E | R&E | The network follows the best practice of preferring R&E routes over commodity. BGP Local Preference favors R&E. | | **Orange (Path)** | R&E | Commodity | The network uses AS-path length to choose, so some destinations use R&E while others route via commodity. R&E and commodity have equal Local Preference. | | **Red (Comm)** | Commodity | Commodity | The network appears to always prefer commodity, even when an R&E route exists. |
Probes that are inconclusive (missing or unexpected return pattern) are excluded from the percentages.
**Orange and red networks are connected to the global R&E network infrastructure, but are not effectively using it.**
## Customer cone percentages
The stacked bar for each AS represents its **customer cone** — the AS itself plus every AS downstream of it in the R&E tree:
- Each probed destination IP is classified as RE, Comm, or Path. - Counts are summed across the entire cone: the AS's own prefixes plus all downstream prefixes. - The three bar segments show each category's share of the cone total, summing to 100%.
A leaf AS shows only its own results. A transit AS near the root aggregates results across hundreds of downstream networks.
## Navigating the report
- **Expand/Collapse:** Click any AS row to expand or collapse its children. Use the "Expand all" and "Collapse all" buttons for bulk control. - **Search:** Type an AS number or name in the search box to highlight matches and auto-expand their location in the tree. - **Sort:** Click the RE, Comm, Path, or Pfx column headers to sort children within each expanded subtree. Click again to reverse direction, a third time to reset. - **Prefixes:** Click the "N pfx" link on any AS to see its originated prefixes. Each prefix links to the per-prefix probe tool. - **Duplicates:** An AS that appears under multiple parents is fully rendered only once. Subsequent appearances show a "see above" link that scrolls to the first occurrence. - **AS names:** Toggle between names and holder names using the "Show AS holder" button.
## Data sources
| Source | Used for | |--------|----------| | [RouteViews](https://www.routeviews.org/) | BGP AS paths and prefix origin data for R&E prefixes | | [RIPE Stat](https://stat.ripe.net/) | AS names and holder information | | [CAIDA AS Organizations](https://www.caida.org/catalog/datasets/as-organizations/) | Fallback AS name data | | lpp-store | Historical LPP probe results used to compute cone percentages |
In the future, the report will be rebuilt daily at UTC midnight.
## Project
This report is part of the [CICI-ROOTBEER](https://www.caida.org/funding/cici-rootbeer/) project.
Steven Wallace Director - Routing Integrity Internet2 ssw@internet2.edu