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CHAPTER 3: PPP Operational Background
Figure 3-1 shows a typical Cisco
®
router with a serial interface configured as a PPP
half-bridge. The router serial interface uses a remote device that supports PPP
bridging to function as a node on the remote Ethernet network. The serial
interface on the Cisco router will have an IP address on the same Ethernet subnet
as the bridge. For example, the customer site is assigned the addresses
192.168.1.0/24 through 192.168.1.1/24. The address 192.168.1.1/24 is also the
default gateway for the remote network. The above settings remove any
routing/forwarding intelligence from the CPE. The associated Cisco configuration
will set serial interface (s0) to accommodate half-bridging for the above example.
Figure 3-1. Cisco router configured as a PPP half-bridge.
Customer site
Service provider’s network
Ethernet LAN
Internet
Router
Bridge
