Cisco Systems C819HG4GVK9 Configuration Example, Enters configuration mode for the Fast Ethernet

Chapter 11 Configuring PPP over Ethernet with NAT

Configuration Example

	Command		Purpose
Step 7
	interface type number		Enters configuration mode for the Fast Ethernet
	Example:		WAN interface (FE4) to be the outside interface
			for NAT.
	Router(config)# interface fastethernet 4
	Router(config-if)#
Step 8
	ip nat {inside outside}		Identifies the specified WAN interface as the NAT
	Example:		outside interface.
			For details about this command and additional
	Router(config-if)# ip nat outside
			parameters that can be set, as well as information
	Router(config-if)#
			about enabling static translation, see Cisco IOS IP
			Command Reference, Volume 1 of 4: Addressing
			and Services.
Step 9
	no shutdown		Enables the configuration changes just made to the
	Example:		Ethernet interface.
	Router(config-if)# no shutdown
	Router(config-if)#
Step 10
	exit		Exits configuration mode for the Fast Ethernet
	Example:		interface.
	Router(config-if)# exit
	Router(config)#
Step 11
	access-listaccess-list-number {deny		Defines a standard access list indicating which
	permit} source [source-wildcard]		addresses need translation.
	Example:		Note	All other addresses are implicitly denied.
	Router(config)# access-list 1 permit
	192.168.1.0	255.255.255.0

Note If you want to use NAT with a virtual-template interface, you must configure a loopback interface. See the “Basic Router Configuration” section on page 5-1for information on configuring a loopback interface.

For complete information on the NAT commands, see the Cisco IOS Release 12.3 documentation set. For more general information on NAT concept, see the “Cisco IOS Software Basic Skills” section on page A-1.

Configuration Example

The following configuration example shows a portion of the configuration file for the PPPoE scenario described in this chapter.

The VLAN interface has an IP address of 192.168.1.1 with a subnet mask of 255.255.255.0. NAT is configured for inside and outside

	Cisco 819 Series Integrated Services Routers Software Configuration Guide
OL-23590-02		11-9