This is the first of three short presentation on routing registries. The Internet Routing Registry (IRR) is a distributed routing database development effort. Data from the Internet Routing Registry may be used by anyone worldwide to help debug, configure, and engineer Internet routing and addressing. The IRR provides a mechanism for validating the contents of BGP announcement messages or mapping an origin AS number to a list of networks. Join AFRINIC’s Amreesh Phokeer for an introduction to routing registry theory and usage.