31 Days Before Your CCNA Exam

274 31 Days Before Your CCNA ExamFigure 8-2Typical Enterprise Internet Connection with a FirewallEnterprise IP NetworkC2www.example.comInternetC3FirewallAccessPointC1However, a firewall by itself is no longer adequate for securing a network. An integrated approachinvolving a firewall, intrusion prevention, and a virtual private network (VPN) might be necessary.An integrated approach to security and the devices necessary to make it happen follow these buildingblocks:■Threat control: Regulates network access, isolates infected systems, prevents intrusions, andprotects assets by counteracting malicious traffic. Cisco devices and applications that providethreat control solutions include the following:— Cisco ASA 5500 series Adaptive Security Appliances (ASA)— Integrated Services Routers (ISR)— Network admission control (NAC)— Cisco Security Agent for Desktops— Cisco intrusion prevention systems■■Secure communications: Secures network endpoints with a VPN. The devices that allow anorganization to deploy a VPN are Cisco ISR routers with a Cisco IOS VPN solution, and theCisco 5500 ASA and Cisco Catalyst 6500 switches.Network admission control: Provides a roles-based method of preventing unauthorizedaccess to a network. Cisco offers a NAC appliance.