Cisco CISCO876-SEC-I-K9 Configuration Guide - Page 47

CH A P T E R 4 Configuring PPP over ATM with NAT The Cisco 857, Cisco 876, Cisco 877, and Cisco 878 access routers support Point-to-Point Protocol over Asynchronous Transfer Mode (PPPoA) clients and network address translation (NAT). Multiple PCs can be connected to the LAN behind the router. Before traffic from the PCs is sent to the PPPoA session, it can be encrypted, filtered, and so forth. PPP over ATM provides a network solution with simplified address handling and straight user verification like a dial network. Figure 4-1 shows a typical deployment scenario with a PPPoA client and NAT configured on the Cisco router. This scenario uses a single static IP address for the ATM connection. Figure 4-1 PPP over ATM with NAT OL-5332-01 92340 4 2 5 ISP 3 6 4 1 2 5 1 Small business with multiple networked devices-desktops, laptop PCs, switches 2 Fast Ethernet LAN interface (inside in3terface for NAT, 192.168.1.1/246) 3 PPPoA Client-Cisco 857, Cisco 876, Cisco 877, or Cisco 878 router 4 Point at which NAT occurs 7 5 ATM WAN interface (outside interface for NAT) 6 PPPoA session between the client and a PPPoA server at the ISP 1 121753 Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide 4-1