With the DE-CIX looking glass service, it is possible to easily search for an AS number, a peer, or a particular IP prefix. In addition, the looking glass service provides information on why a certain route is rejected by the route server (e.g. due to IRR filters). Below you can find a detailed explanation of how to use the looking glass, how to narrow down search results, what exactly you can see, some typical search examples, and more information about query strings and how to use the API in your own scripts.
The DE-CIX Looking Glass utilizes the open source projects Alice-LG and birdwatcher. A big thank you to all who contributed to these projects!