CCSP Self-Study: Securing Cisco IOS Networks (SECUR)

Using Routers to Secure the Network

This section considers different router topologies that can be used to secure a network, including a standalone perimeter router; a perimeter router and firewall; a perimeter router with integrated firewall; and a perimeter router, firewall, and internal firewall.

Standalone Perimeter Router

The most basic routed network consists of a corporate LAN connected to the Internet using a single perimeter router. This router must secure the corporate network (trusted network) from malicious activity originating on the Internet (untrusted network). Installations of this type, shown in Figure 4-1, are typical of small enterprises.

Figure 4-1. Standalone Perimeter Router

The perimeter router, being the only line of ...