---
title: Glossary · Cloudflare BYOIP docs
description: Review the definitions for terms used across Cloudflare's BYOIP documentation.
lastUpdated: 2024-10-30T13:44:50.000Z
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source_url:
  html: https://developers.cloudflare.com/byoip/glossary/
  md: https://developers.cloudflare.com/byoip/glossary/index.md
---

Review the definitions for terms used across Cloudflare's BYOIP documentation.

| Term | Definition |
| - | - |
| address map | A data structure enabling customers with BYOIP prefixes or account-level static IPs to specify which IP addresses should be mapped to DNS records when they are proxied through Cloudflare. |
| autonomous system numbers (ASNs) | A large network or group of networks that has a unified routing policy. Every computer or device that connects to the Internet is connected to an autonomous system. |
| Border Gateway Protocol (BGP) | The routing protocol for the Internet, which is responsible for picking the most efficient routes to deliver Internet traffic. |
| Internet Routing Registry (IRR) | A globally distributed database of routing information which contains announced routes and routing policies in a common format. Network operators use this information, as well as [RPKI](https://developers.cloudflare.com/byoip/concepts/route-filtering-rpki/), to configure backbone routers. |
| Resource Public Key Infrastructure (RPKI) | A cryptographic method of signing records that associate a route with an originating autonomous system number. |
| Route Origin Authorization (ROA) | The RPKI-signed object that states an autonomous system is authorized to originate a particular IP address prefix or set of prefixes. |
| Unicast Reverse Path Forwarding (uRPF) | A security feature that can prevent spoofing attacks. |
