CHAPT ER
3-1
Cisco Secure Router 520 Series Software Configuration Guide
OL-14210-01
3
Configuring PPP over Ethernet with NAT
The Cisco Secure Router 520 Ethernet-to-Ethernet routers support Point-to-Point Protocol over Ethernet
(PPPoE) clients and network address translation (NAT).
Multiple PCs can be connected to the LAN behind the router. Before the traffic from these PCs is sent
to the PPPoE session, it can be encrypted, filtered, and so forth. Figure 3-1 shows a typical deployment
scenario with a PPPoE client and NAT configured on the Cisco router.
Figure 3-1 PPP over Ethernet with NAT
1Multiple networked devices—Desktops, laptop PCs, switches
2Fast Ethernet LAN interface (inside interface for NAT)
3PPPoE client—Cisco Secure Router 520 Ethernet-to-Ethernet router
4Point at which NAT occurs
5Fast Ethernet WAN interface (outside interface for NAT)
6Cable modem or other server (for example, a Cisco 6400 server) that is connected to the Internet
7PPPoE session between the client and a PPPoE server
121753
2
3
5
6
1
7
4
Internet