This document discusses security issues and solutions for Internet service providers (ISPs). It covers: 1. Implementing security on the control plane and data plane from both physical and logical positions. This includes securing routers, routing information, and event logging. 2. Examples of control plane security include router access control lists, authenticated routing protocols, route validation databases, and limiting route prefixes. 3. Data plane security focuses on preventing unauthorized packet flows and denial of service attacks on the ISP network.